Homes and small projects
Establish the energy-compliance route for an extension or conversion, including glazing and compensatory calculations where appropriate.
A domestic project can need an energy assessment even when it is not a new home. The route depends on the proposed glazing, retained building, new thermal elements, services and the approach accepted by building control.
We review the proposal and explain whether a calculation is likely to be required, what it needs to demonstrate and which information is still missing. Where a whole-dwelling or compensatory calculation is appropriate, we compare the proposed dwelling and extension with the same existing dwelling plus a compliant reference extension, using the baseline required by the applicable method. This is a design and compliance service, not an existing-home RdSAP EPC survey.
Large openings can exceed the area accommodated by a straightforward elemental route. A calculation may show how improved fabric or other measures compensate, subject to the applicable requirements and building-control agreement.
Plans, construction age, retained elements, heating systems and any known upgrades help establish the baseline. We make uncertainty visible and request evidence where it matters.
We explain the relative effect of glazing, insulation, junctions and services so the architect or homeowner can choose changes that suit the project rather than chase a number blindly.
Existing and proposed drawings must describe the same whole building. Missing retained rooms, removed openings or earlier insulation upgrades can change a compensatory calculation and should be resolved before options are compared.
A clear description of the agreed assessment approach and the information on which it relies.
The relevant calculation with proportionate design feedback where changes are needed.
A report suitable for the agreed building-control purpose, with assumptions and specifications recorded.
Getting started
Dimensioned floor plans, elevations and sections showing retained, altered and new work.
Known build-ups, U-values, window specifications, heating and hot-water systems, and evidence of previous upgrades where relevant.
Site location, building-control comments, planning constraints and the intended construction programme.
No. The need depends on the project and compliance route. Send the drawings and building-control requirement and we can confirm the likely scope.
Yes. Early advice is useful where the architectural intent includes extensive glazing or limited space for insulation.
No. The online extension calculator is an early design aid. A formal submission needs project-specific information and the appropriate professional calculation.
The fee and programme depend on the building, drawing quality, glazing strategy, route requested by building control and number of options to test. Send the existing and proposed plans plus any building-control comment for a written scope.
Use the edition, jurisdiction and assessment route that apply to the project. Publication of newer guidance does not automatically change an existing project’s requirements.
Share your existing and proposed drawings. We will tell you what assessment is likely to be useful and what information it needs.