In short and in plain language
This article is about heat pumps in the garden. The outdoor unit needs work from a landscaper.
That means a foundation and a gravel bed for the water from the unit. A trench for the pipes is part of it too. You agree this with the heating installer.
There are rules on the distance to the boundary. There are also limits for noise at the neighbour's window.
For funding, the foundation counts, the garden does not. Separate items on the invoice help the customer.
We build a service page for this work, with a form.
In the first half of 2026, manufacturers in Germany sold 40 per cent more heat pumps to wholesalers or specialist installers than in the same period a year earlier (BWP). The German heating industry association counts 194,500 heating heat pumps sold from January to June (BDH). These are sales figures, not installed systems, but they show the direction: many of these units will end up in a garden. And an outdoor unit needs more than a power supply. It needs a load-bearing base, somewhere for the condensate to go, a trench for the pipes and cables, a position that keeps its distance from the boundary and from the bedroom window next door, and finally a place in the path, lawn and planting. That is work for a landscaping business. Many firms already do it, as a favour for the heating installer or as one line in a quote. It rarely appears on their website. This article shows which parts of the installation belong in the garden, which rules apply and how to turn the work into a service page of its own.
Key takeaways
- In the first half of 2026, manufacturers sold 40 per cent more heat pumps to wholesalers and specialist trades than a year earlier (BWP). Every outdoor unit in a garden needs work there: base, condensate, trench.
- In Lower Saxony, free-standing heat pumps including foundation and enclosure up to 2 m high may stand closer than 3 m to the boundary where there is no other option, over no more than 3 m of boundary length and without unreasonable effects on the neighbour (Sec. 5 NBauO).
- Noise is assessed 0.5 m outside the window next door (LAI). In a general residential area the night-time guide value is 40 dB(A), in a purely residential area 35 dB(A) (TA Lärm).
- Foundation, gravel bed for condensate and the pipe trench are construction jobs the landscaper agrees with the heating installer: position, height, decoupling, drainage and access for servicing.
- For subsidies, foundation and enclosure count as part of the heat pump, while work on outdoor facilities and open spaces does not (KfW). Separate invoice items make the customer’s application easier.
- A dedicated service page with the process, the hand-offs to the heating trade and a form for unit details, site photo and boundary distance turns a side job into a visible order.
Why the outdoor unit is a garden matter
The figures for the first half of 2026 are clear. From January to June, 352,000 heat generators were sold in Germany, 194,500 of them heating heat pumps (BDH). Heat pumps thus made up more than half of total sales (BDH). The German Heat Pump Association reports an increase of 40 per cent on the same period of the previous year for the same statistics and makes clear that this refers to manufacturers’ sales to wholesalers or specialist installers (BWP). The figure does not say how many units will actually be running by the end of the year. It does say how many systems are on their way to a building site right now.
Most of them are likely to work with outdoor air: among new installations in 2022, air was the heat source in around 80 per cent of cases (Umweltbundesamt). The federal and state working group on emission control notes that air-source heat pumps are usually installed outdoors and are gradually replacing old oil and gas boilers in existing homes (LAI). In total, just under two million heat pumps are currently in use in Germany (BWP). Every new air-source heat pump with an outdoor unit is therefore a device that needs a place somewhere between the house wall, the patio and the plot boundary.
For landscapers this is work at the heart of the core business. Private gardens remained the largest client segment in 2025, at 56.87 per cent of the sector’s turnover (BGL). The customers planning a heat pump now are often the same owners who already have their garden laid out, remodelled or maintained by a specialist firm. They face a question the heating installer only partly answers: where should the unit go, and what will the garden look like afterwards?
The heating installer plans the unit, the hydraulics and the electrics. The work in the ground and on the surface sits in between. Sometimes the heating firm does it with its own crew, sometimes a subcontractor, and sometimes it lands on the owner, who then stands in the garden with a bag of ready-mix concrete and a wheelbarrow. A landscaping business that names this gap on its website gets found for an enquiry that would otherwise end with the heating installer or not be made at all.
The position: boundary distance under Sec. 5 NBauO
In Lower Saxony, the heat pump is both simple and demanding under building law. Simple, because the annex to the building code lists it among the procedure-free building works: a heat pump needs no building permit (NBauO, Annex No. 2.2). Demanding, because procedure-free does not mean rule-free. Procedure-free works must still meet the requirements of public building law, and that duty lies with the owner (KEAN). What this means for garden sheds, patio roofs and pools is covered in Garden sheds, patio roofs, pools: what needs no permit.
The standard distance to the plot boundary is 0.4 H, but at least 3 m (Sec. 5 NBauO). Since June 2023 there has been a separate exception for heat pumps (KEAN). Free-standing heat pumps including their foundations and enclosures up to a height of 2 m may stand with no distance or with a distance reduced to as little as 1 m (Sec. 5 NBauO). The exception has two conditions: the regular distances cannot otherwise be kept on the plot, and no unreasonable impairment arises on neighbouring plots, in particular from ice formation, noise and exhaust air.
free-standing heat pumps including their foundations and enclosures up to a height of 2 m, provided that a) the distances under paragraphs 1 to 7 cannot otherwise be kept on the building plot and b) no unreasonable impairment arises on the neighbouring plots, in particular from ice formation, noise and exhaust air.
For landscapers, this sentence contains two jobs. First, foundation and enclosure count towards the height. Anyone who builds a tall plinth against snow and splash water and adds a louvred housing on top may push the unit out of the exception. Second, the length is limited. Structures under this exception may fall short of the distance over 9 m per boundary, and heat pumps only over a total length of 3 m of that (Sec. 5 NBauO). An enclosure that runs along the boundary as a privacy screen uses up this allowance quickly.
The Climate Protection and Energy Agency of Lower Saxony sums up the practice like this: smaller heat pumps up to 1 metre high are generally exempt from the distance rule, and for medium-sized units owners should first check whether the plot offers a position 3 metres from the boundary (KEAN). That check works better in the garden than at a desk. Where are the hedge, fence, shed and patio? Where does the boundary actually run, and where is the nearest window next door? Whoever knows the garden knows the answer.
Other states, other measures
Noise: what TA Lärm measures at the neighbour’s window
The boundary distance is building law. Noise is emission control, and there the window counts, not the boundary. Air-source heat pumps need no permit under emission control law and are assessed under TA Lärm, the technical instructions on noise (LfU Bayern). The relevant point is 0.5 m outside the window of the living room, bedroom, study or children’s room most affected by the noise (LAI). Guide values for day and night apply there depending on the type of area, with night running from 10 pm to 6 am (TA Lärm).
| Area (TA Lärm, No. 6.1) | Day, 6 am to 10 pm | Night, 10 pm to 6 am |
|---|---|---|
| Purely residential area | 50 dB(A) | 35 dB(A) |
| General residential area, small settlement area | 55 dB(A) | 40 dB(A) |
| Core, village and mixed area | 60 dB(A) | 45 dB(A) |
Because the guide values are lower at night, night time is usually decisive for air-source heat pumps (LfU Bayern). Complaints arise mainly at night, which is why the LAI guideline is built around the night-time values (LAI). What reaches the window depends on three factors, all of them related to the garden: the sound power level of the unit, the distance and the surroundings of the installation spot.
- The unit: The Bavarian State Office for the Environment recommends a sound power level of no more than 50 dB(A) for air-source heat pumps in modern detached houses and points out that most systems are considerably louder (LfU Bayern). The German Environment Agency describes a sound power from 50 dB(A) outside the house as potentially problematic for the neighbourhood (Umweltbundesamt).
- The distance: For a unit at 50 dB(A) without tonal noise, installed near a wall, the LfU gives a minimum distance to sensitive buildings of 3 m in a general and 6 m in a purely residential area (LfU Bayern).
- The surroundings: Directly in front of a house wall, the sound pressure level rises by 3 dB, with two nearby walls by 6 dB (LfU Bayern). Placing the unit on the side of the house facing away from the neighbour lowers it by up to 20 dB compared with a position directly opposite the neighbouring house (LfU Bayern).
The corner between garage and house, sheltered, inconspicuous and close to the plant room, is therefore often the worst place acoustically. The consumer advice centre explicitly advises against placing the unit between two walls, because echo effects increase the volume; lawns, on the other hand, have a damping effect (Verbraucherzentrale). It considers a minimum distance of three to four metres from bedrooms and neighbouring buildings advisable, together with the manufacturer’s noise data (Verbraucherzentrale). For landscapers this means: the position is a design decision with acoustic consequences. The calculation is done by the specialist planner or the heating installer; the garden provides the space for the result.
A calculation instead of a hunch
Foundation, gravel bed and condensate
The outdoor unit stands on a foundation or plinth. Dimensions, depth and height above ground are set by the manufacturer’s installation manual, and the build follows it. What the landscaper adds is what a heating installer rarely carries on the van: excavation, a frost-proof base, compacted sub-base, formwork or a precast element, and a clean connection to the surrounding surface.
Two points turn a concrete plinth into a landscaping job. The first is decoupling. The LfU describes decoupling structure-borne noise in outdoor installations as particularly necessary when the unit is mounted directly on the wall or the foundation is directly connected to the building (LfU Bayern). A plinth cast against the house wall or the basement entrance can carry vibration into the house. A joint to the building and a separate base are therefore not a detail but part of the job.
The second point is water. During operation and defrosting, the outdoor unit produces condensate that has to go somewhere. The installation manual specifies whether it may drip freely, be piped into a soakaway or be connected to the property drainage. The Lower Saxony building code explicitly names ice formation as a possible unreasonable impairment for the neighbouring plot (Sec. 5 NBauO). What applies to the neighbour applies all the more to your own path: a unit whose condensate runs onto the paving in winter creates a sheet of ice exactly where people walk to the bins in the morning.
A gravel bed or soakaway under and next to the unit takes up the water if the soil lets it drain. Cohesive soils need a drain or a connection to the drainage system, depending on the local by-laws. Which details make an infiltration quote calculable is explained in Rainwater infiltration: swales, soakaways and tanks; the small gravel bed under a heat pump raises the same basic questions on a smaller scale.
Base
Excavation and a frost-proof base as specified by the manufacturer, compacted sub-base, foundation or precast plinth. The height above ground protects against snow and splash water and counts towards the permitted height at the boundary.
Decoupling
A separate base with no rigid connection to the house wall, a joint to the building, buffers between unit and plinth as specified by the manufacturer. That keeps structure-borne noise outside.
Condensate
Gravel bed or soakaway, drainage to frost-free depth as per the installation manual, a drain or connection to the drainage system on cohesive soil. No water on paths, no water running to the neighbour.
Service access
Clear space in front of the intake and exhaust sides, firm access with stepping stones or paving, no plants growing into the unit. The service engineer should reach the unit without stepping into a bed.
Pipe trench and path connection
Between the outdoor unit and the house run pipes, either refrigerant or water lines depending on the design, plus the electrics. The consumer advice centre recommends keeping the distance to the house as short as possible, because every additional metre increases heat losses through the outdoor pipes (Verbraucherzentrale). That sentence limits the freedom of choice: the quietest spot at the far end of the garden is rarely the right one in energy terms.
Depth, bedding and protection of the pipes are specified by the heating firm or the electrician. The landscaper takes care of excavation, backfilling and the surface, and knows where pipes, drains or roots already lie under the lawn. Where the trench crosses paving, the paving is lifted and relaid instead of living with a patch. Where it crosses lawn, reinstatement including reseeding belongs in the same quote, not in a later invoice.
Then there is the airflow. The consumer advice centre recommends keeping the fan openings at a minimum distance from footpaths and the patio, because the draught right next to the unit can affect comfort, and making sure the prevailing wind does not blow towards the exhaust opening (Verbraucherzentrale). These are planning questions for the garden: where does the path run, where do people sit in the evening, and where does the area in front of the unit stay clear? A unit that blows cold air onto the garden bench is a nuisance every time someone sits outside during the heating season.
Screening and planting at a distance
Hardly any owner wants to see the unit from the living room. The consumer advice centre names covers, walls or hedges as noise measures that can lower the volume significantly (Verbraucherzentrale), and the LfU notes that disturbing operating noise is reduced when there is no direct line of sight to sensitive rooms next door (LfU Bayern). This creates a design task with two sides.
One side is the airflow. An outdoor unit needs freely flowing intake air and a clear exhaust side; the consumer advice centre advises keeping the fan openings accessible so that air flows are not obstructed (Verbraucherzentrale). A dense hedge right in front of the intake grille pleases the eye and harms the system. The manufacturer gives the minimum clearances around the unit in the installation manual, and the planting plan follows them, not the other way round. Spread means the width of the mature plant, not the width on planting day.
The other side is reflection. A closed wall close behind the unit acts as an additional reflecting surface, and every such surface raises the level (LfU Bayern). A noise barrier works when it stands between the unit and the assessment point and has been sized by a specialist planner. Louvres, gabions or a timber wall are therefore components with a function: the planner sets the function, and the landscaper builds it and fits it into the garden.
If the firm plants a hedge along the boundary, neighbour law applies as well. In Lower Saxony, the boundary distance for trees, shrubs and living hedges up to 2 m high is 0.50 m (NNachbG). The full scale is set out in Boundary distances for trees and hedges explained. Choosing plants around a unit that blows out cold air during the heating season raises the same site questions as anywhere else in the garden; how to explain such a choice on your website is shown in Drought-tolerant planting as a garden service.
Subsidies and invoice: foundation yes, garden no
Many owners apply for a grant for their heat pump under the federal programme for efficient buildings (BEG). For landscapers, one distinction in the KfW information sheet on eligible measures matters. For individual measures, a heat generation system also includes necessary technical work and materials such as transport, mounting, substructure, foundation and enclosure (KfW). By contrast, all preparatory work to prepare or open up the plot and all measures on outdoor facilities and open spaces are not eligible as ancillary measures (KfW).
For the invoice this means: foundation and enclosure belong to the heat pump, and for individual measures all eligible expenditure must be allocated to the heat generator on the invoice (KfW). Paths, planting and screening for design reasons are outdoor facilities. The allocation is less clear for the pipe trench and for reinstating the surface above it: the information sheet counts all measures directly required for the installation as part of the system and funds restoration work connected with the energy measure as an ancillary measure, but excludes measures on outdoor facilities (KfW). How these items are classified is settled by the expert who confirms the application. Billing the system and the outdoor works as one lump sum forces the customer or their energy adviser to split the invoice afterwards. Quoting separately delivers the split right away, and that gets around among heating installers and energy advisers.
A note, not subsidy or tax advice
For the part that is not subsidised, the tax relief for tradespeople’s services may play a role. It amounts to 20 per cent of the costs, up to 1,200 euros (Sec. 35a EStG), and covers labour costs only, not materials (Sec. 35a EStG). It does not apply to publicly funded measures for which reduced-interest loans or tax-free grants are claimed (Sec. 35a EStG). Whether and for which part of the work the customer can use it is for them to clarify with their tax adviser. What the invoice needs so that the question can be answered at all is covered in Section 35a tax relief: labour costs on the invoice.
The service page for heat pumps in the garden
The service has a clear trigger and a clear customer: owners who have ordered or are planning an air-source heat pump. They are not searching for landscaping but for a solution to a specific problem: where to put the unit, who does the foundation, how to get it out of sight. A dedicated page on your landscaping website answers these questions in the order they come up, and it fits naturally under the page for private gardens.
Settle the position
Boundary distance under Sec. 5 NBauO, distance to the window next door, route to the house, airflow. Together with the heating installer and before the first spade goes in.
Foundation and condensate
Base as specified by the manufacturer, decoupled from the building, gravel bed or soakaway, frost-free drainage, firm access for servicing.
Trench and connection
Excavation for pipes as specified by the heating firm, backfilling, reinstating lawn and paving, clean connections to paths and patio.
Screening and noise
Louvres, wall or planting with clearance from the intake and exhaust sides. Noise barriers sized by the specialist planner, designed to suit the garden.
Handover
Photos of the base and gravel bed before backfilling, a site plan with position and boundary distance, separate invoice items for the system and the outdoor works.
Boundary distance under Sec. 5 NBauO, distance to the window next door, route to the house, airflow. Together with the heating installer and before the first spade goes in.
Base as specified by the manufacturer, decoupled from the building, gravel bed or soakaway, frost-free drainage, firm access for servicing.
Excavation for pipes as specified by the heating firm, backfilling, reinstating lawn and paving, clean connections to paths and patio.
Louvres, wall or planting with clearance from the intake and exhaust sides. Noise barriers sized by the specialist planner, designed to suit the garden.
Photos of the base and gravel bed before backfilling, a site plan with position and boundary distance, separate invoice items for the system and the outdoor works.
The page should also say what the firm does not do. It does not install the unit, connect anything or calculate a noise forecast. This boundary is not a weakness but the argument for working together: the customer sees that the interface with the heating installer has been thought through. The LAI recommends documenting the noise check with a site plan showing the position of the heat pump, the assessment points and the obstacles in the path of the sound (LAI). A landscaping business that works with site plans anyway can supply this document.
For the pictures, the same applies as for any service page: show the work, not products. The photo of the finished heat pump in front of the hedge is good; more important are shots of the base, the gravel bed and the trench before everything is backfilled. How to get such pictures is covered under photos for your website; the portfolio gallery deserves its own category for this. If you want to show the finished installation from the air, check aviation law first, see Drone flights over customer gardens: aviation law before the photo shoot.
The details an enquiry should bring
An enquiry about a heat pump in the garden can rarely be answered in full without a site visit. It can, however, be well prepared. The enquiry form asks for the details the customer already has or can provide with a photo.
- Unit: manufacturer and model, dimensions, weight and sound power level, or simply a photo of the data sheet.
- Planning status: has the heat pump been ordered, who is the heating installer, is there an installation date?
- Position: photo of the planned spot with house wall and surroundings, approximate distance to the boundary.
- Ground: lawn, bed, paving or gravel at the spot, known pipes or drains.
- Services wanted: foundation, gravel bed, pipe trench, screening, planting, reinstatement.
- Area: development plan or type of area if known; otherwise the address is enough.
With these details you can assess in advance whether the boundary exception is an option at all, whether a gravel bed will do and whether the date with the heating installer can be met. The site visit becomes shorter and the quote needs fewer follow-up questions. If you like, add a field for the planned installation date; the enquiry then sorts itself into the weekly schedule.
Clarify the hand-offs with the heating installer
Most misunderstandings happen at the transitions. A table on the service page, or at least in the quote, creates clarity before two crews stand in front of the same hole on the same morning.
| Task | Landscaping business | Heating installer |
|---|---|---|
| Choice of position | Garden plan, boundary line, paths, planting | Unit, pipe lengths, noise forecast |
| Foundation or plinth | Excavation, base, construction to specification | Dimensions and position as per manufacturer |
| Condensate | Gravel bed, soakaway, drain | Connection at the unit, frost protection at the outlet |
| Pipe trench | Excavation, backfilling, surface | Pipes, insulation, wall entry into the house |
| Screening and noise | Louvres, wall, planting | Sizing of noise barriers, cover on the unit |
| Completion | Paths, lawn, paving, photos | Commissioning, handover briefing |
Agreeing this split once with the heating installers in your region wins you more than one job. You become the contact the heating firm passes its customers to, because work in the garden is not part of its core business. The service page then also proves to these partners that you have understood the task, and it is a link they can send to their customers.
Where garden installations go wrong
Plinth against the house wall
A plinth cast against the wall carries structure-borne noise into the house. A separate base with a joint to the building is the better choice.
Unit in the corner
With two nearby walls the level rises by 6 dB compared with a position without nearby walls (LfU Bayern). The corner is convenient, but loud.
Condensate on the path
Without a gravel bed or drain the water freezes on paving and slabs in winter. Drainage belongs in the plan, not in the remedial work.
Hedge in front of the grille
Plants at the intake or exhaust side obstruct the airflow. Plan clearances as per the installation manual, using tomorrow’s spread.
Enclosure too tall
Foundation and enclosure count towards the 2 m height up to which the boundary exception applies (Sec. 5 NBauO).
One lump sum for everything
Foundation and garden in one total complicate the subsidy application and the tax return. Show the system and the outdoor works separately.
What the customer ends up with in the garden
In the end there is a unit on a foundation that does not cling to the house wall, next to a gravel bed that swallows its water, reachable by a path that does not ice over in winter, and behind a design that keeps the airflow clear and does not draw the eye to the unit. Add a site plan, photos of the base and an invoice that separates the system from the outdoor works.
None of this is new to a landscaping business. What is new is the occasion, and it is growing: with 194,500 heating heat pumps sold in the first half of 2026 (BDH), many gardens face the question of who does the work outside. In 2025, Germany had 19,898 landscaping businesses (BGL). Which of them gets asked about the heat pump in the garden is often decided before the first phone call: on the page the customer finds when searching for a foundation, gravel bed or screening for their outdoor unit. We are happy to show how such a page fits into a landscaping website for your range of services.
Sources and Studies
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