Design support for new build domestic dwellings across our product range.

Our team can provide technical drawings and specification advice for house builders and developers of medium to large scale projects. All of our team are authorised SAP assessors and hold the IDHEE Domestic Heating Design Certificate. Services provided range from product specification to fully indemnified system designs and include:

Gas and oil fired boiler systems:

  • Radiator sizing and pipe work layout

Heat pump systems:

  • Heat pump and collector sizing
  • Estimated annual running costs
  • Heating system working drawings

Solar thermal systems:

  • Cylinder size and number of panels
  • Annual solar input
  • Annual costs and CO2 savings
  • RHI benefit

Total designs completed


Designs completed in last 12 months


Heat pump sizings completed

Central Heating Design Service

We offer an indemnified central heating design service to housebuilders and specifiers of new build dwellings.

Please note that the central heating design service is available for multiple designs only. It is not available for one-off house designs, existing houses, extensions or non-domestic applications.

The service can include:

  • System schematic drawings
  • Radiator placements
  • Heat loss calculation
  • Equipment schedule
  • Pipework layout
  • Heat pump sizing
  • Solar Sizing and RHI Information

Our in-house design team prepares the drawings in accordance with appropriate building standards and regulations.

The software used has been specifically designed to accommodate the industry’s requirements for full central heating design and associated documentation.

Designs are available in hard copy or electronically, and the lead time for a full design is up to 4 weeks.

Search for a local contact to enquire about this service.
SAP guide

2018 SAP Guide

With simplicity and transparency in mind, we have constructed a handy guide. Designed to assist SAP assessors in identifying key up to date efficiency figures for our heating products, controls and accessories. All figures are as illustrated in the Products Characteristic’s Database (PCDB).

Download New 2018 SAP Guide

Heat Pump Sizing Services


Standard sizing service

On receipt of your survey form we will proceed to calculate:

  • The size of heat pump required
  • The amount of ground collection material required (horizontal pipe length, or bore hole depth for ground source)
  • The estimated annual running cost of the heat pump

This can take up to 2 days to process. Please note - it is essential that the survey information is accurate as this provides the basis for the sizing calculation.


Detailed design service

We are also able to offer a comprehensive design service costing £250, where you will receive:

  • Heat pump sizing calculation (as with standard service)
  • Full system details
  • Heating system working drawings
  • Hot and cold pipe runs

This service requires the submission of full scaled plans and elevations in addition to the completed survey and is fully refundable upon purchase of the heat pump from the merchant. This service can take up to 4 weeks.

Viability of using the heat pump sizing service

Heat pumps are generally suitable for new build, refurbishment or conversion projects. They should ideally be used in conjunction with underfloor heating to give maximum efficiency. (Radiators can be used, however outputs must be increased to cope with the lower temperatures supplied by heat pumps.)

Levels of insulation up to or exceeding current building standards are usually required throughout the property and we therefore advise contacting our Renewables Team on 0330 123 9229 to discuss the project in detail in the first instance.

If after the discussion the proposal appears to be viable, the sizing form should be completed with reference to the guidance notes and e-mailed to

Download heat pump sizing form
Local Contacts

Find your local Technical Sales Manager

To find your local Commercial Sales Manager, please use the search below. All of our local Commercial Sales Managers are experts on our products and services and will be happy to provide any support or advice you need.

Please note that this search is for installers only. If you are a homeowner looking for an installer, please use our Find an Installer search in the homeowner area of the website.

Want to know more about working with Worcester?

If you have any questions at all, you can either send us an enquiry using our online form, or give our support team a call on 0330 123 9339.