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How to write a brief for a renewable heat system

Posted by Tasha Kosviner on 22 January 2014 at 9:05 am

Once you have decided that you’d like to install a renewable heating system in your home or office, it’s a good idea to write a brief for the project. Rather than detailing all the various technologies you’ll need, a brief is designed to set out your expectations and can be a benchmark against which the success of your project is measured. 

Installers can use the brief to provide you with their recommendations and, eventually, a quote and it will help you when evaluating different quotes and working out which best suits your needs. 

1. Outline of your project

Use this space to include details such as whether your project is domestic or commercial, whether it’s new build or a retrofit. Include what you’d like to achieve with your installation, for example heating a three-bedroom house, heating a swimming pool, generating electricity and so on and what system, if any, is being replaced. 

2. Budget

You may choose not to share this information with potential contractors for the purposes of the quote but you should have an idea of how much it will cost before you start looking for quotes. Use the first table below to work out roughly what sized system you’ll need according to the age and floor area of your house, and see the second table to give you an idea of the average cost of a 10kW system.

3. Energy efficiency standards 

Your local planning authority will be able to tell you what minimum standards you need to meet. For new builds, these will probably include Part L for the conservation of heat and power in domestic buildings or the SBEN/BREEAM Standard for commercial buildings. Other more stringent standards you may wish a new build to meet include the Code for Sustainable Homes and the Passive Haus Standard.

4. Planning restrictions

In addition to the energy efficiency standards noted above, make a note of any planning restrictions that may apply to your project, for example if the building is listed or lies within a conservation area. If you are looking at water source heat pump, use this space to note what permission has been sought from the environment agency.

5. Return on investment

Newly installed renewable heating systems will qualify for renewable heat premium payments and/or the renewable heat initiative (RHI), providing they meet certain standards. If you'd like to receive these payments, and why wouldn't you, then make sure that you stipulate that your installation must be made by an MCS-approved installer and that your whole property must be adequately insulated. Your insulation will need to be checked by an assessor as part of the RHI application process, as will your MCS certification and you will not qualify if the necessary standards are not met. If your installer is not aware of these standards you may not consider them the right company for the job.

6. Site restrictions

The type of system you settle on could well be dictated by the geography of your site. Biomass boilers, even on a domestic scale, require a large dedicated shed for fuel storage with space for deliveries. Ground source heat pumps will require digging up land to install a ground loop connector (as a guide, you will attain 25W per square metre and up to 50W per lineal metre of bore hole) while air source heat pumps have a relatively small footprint and are easy to install. However, they tend to produce slightly more noise than ground source machines so it is worth considering the position of the outdoor unit to minimise noise disruption. When it comes to solar thermal (for heat and hot water, as opposed to solar electricity) you will need at least five square metres of un-shaded south facing roof to make any significant contribution to hot water production.

7. Performance requirements

Make a note of how you currently heat your house, for example whether it’s on all day or only in the mornings and evenings, and whether you’re prepared to be flexible with this pattern to attain a more efficient system. For example, most heat pumps run more efficiently if they are on all the time, at a lower temperature. You may also need to decide whether you can use your existing radiators or go to the expense of installing larger ones which will run more efficiently with a heat pump. 

8. Extra controls

Finally you should look at how you’d like to control your system. Zoned thermostats that allow you to control the temperature in each room, or on each floor, independently are useful, while a system that allows you to set different flow temperatures at different times of the day could be useful too. Some manufacturers, such as Stiebel Eltron, have a range of heat pumps that incorporate an internet service gateway to allow remote tracking of performance, system control and can automatically contact your service engineer if it detects a fault. 

This article is based on a guide produced by John Felgate of Stiebel Eltron, who is the Chairman of the Domestic Heat Pump Association. You can download the more detailed version here.  

Photo Credit: Gareth-Davies via Compfight cc

More information

YouGen guide to renewable energy

YouGen guide to the renewable heat incentive

If you have a question about anything in the above blog, please ask it in the comments section below.

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7 comments - read them below or add one

Cathy Debenham

Cathy DebenhamComment left on: 25 February 2014 at 1:49 pm


This has just arrived from DECC:

"We are pleased to announce that the regulations governing the domestic Renewable Heat Incentive (RHI) scheme have now been laid in Parliament – a critical step towards achieving our aim to open the scheme for applications this spring.

"As part of the process necessary to implement the scheme, approval from the European Commission is required. This is because the RHI falls under EU ‘state aid’ rules that control certain types of government support.  The European Commission has granted state aid approval for the domestic RHI, although third party owners of renewable heating systems were not included in this decision. Third party owner means anyone who does not own or occupy the property to which the renewable heating system provides heat.

"Rather than risk further delay to the launch of the domestic RHI we will proceed on the basis of the Commission’s decision, which will mean third party owners will not be eligible to apply when the scheme opens this spring. It is still our intention to include this group in the scheme, however, and we are currently looking at options as to how best to achieve this and when we will be able to make such changes.

"This does not impact on homeowners who have secured financing for their renewable heating system through a third party, but rather refers to models where a third party retains ownership of the renewable heating system and claims the domestic RHI directly for that installation.  Private and social landlords come under a different category, and will still be eligible for the domestic RHI because they own the properties in which the technology is installed."

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Cathy Debenham

Cathy DebenhamComment left on: 25 February 2014 at 12:59 pm

Hi Ellwood

Further to my answer this morning, I've just learned some more about this, and the situation isn't clear. The DECC document published in July 2013 said third party ownership was OK. However, the draft legislation just published indicates it's not that simple. Here's an update I've just received: 

"It does seem that third party ownership is either excluded now or is very complex.   The legislation was fairly clear, the applicant must have paid for some or all of the plant (it doesn’t stipulate how much) AND must be the owner or occupier of the heat demand. This would suggest to me that a third party could still own the bulk of the plant, but could not receive the RHI payments. IN addition, the applicant would be liable for that plant.   Specifically in the draft legislation:   “An owner of a plant which meets the eligibility criteria may apply to the Authority for that plant to be given accreditation if that person owns or occupies the property to which the plant provides heat. ”   but also,   “if the plant is owned by more than one person, such evidence as the Authority may require that the accreditation application is made by only one of those owners and that the owner who is making the accreditation application has the authority from all other owners to be the participant.”   So the owner could be multiple people, but it looks like the applicant must be responsible for the plant as well as being the home occupier/owner – tricky for third party ownership.   This really doesn’t chime with previous details of the d-RHI (as you rightly point out, third party system owners were supposed to be able to apply), so I’m looking to get clarification."   I'll update here as I learn more.

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Cathy Debenham

Cathy DebenhamComment left on: 25 February 2014 at 9:12 am

Hi Ellwood

One of the eligible categories is 'third party owners'. This is when a system is leased - and is similar to the solar PV rent a roof model. For example, rather than buying a biomass boiler (or other heating system), you would lease it, and the company that owned it would get the RHI payments. The owner could be an installer. I hope this clarifies things. 

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ellwoodComment left on: 24 February 2014 at 12:07 pm

Thanks Tasha,

Trying not to labour the point, but If the appllicant is the owner of the equipment and it is the installer, not the householder, who owns the equipment the installer claims the RHI payments.



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Tasha Kosviner

Tasha KosvinerComment left on: 12 February 2014 at 2:15 pm

Latest from DECC:

"The bank account has to be in the name of the applicant. Ofgem will do full ID checks to make sure this is the case."

I'm guessing that's a no then, ellwood!

Hope that answers your question.

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Tasha Kosviner

Tasha KosvinerComment left on: 10 February 2014 at 2:45 pm

Hi ellwood

The word coming back from DECC is that it is not possible to assign payments elsewhere. I've asked for clarification on why you can't just put another bank account no on your application form and they're getting back to me. More info as it comes in! 


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ellwoodComment left on: 7 February 2014 at 1:43 pm

Hi Tasha,

Do you know if it is possible to assign domestic RHI, deemed heat useage,

payments to a third party ie lenders of the money or the installers themselves.


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