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We work with homeowners, developers, builders and architects on residential projects, including new homes, extensions, conversions and renovations. You can contact us about one assessment or several coordinated services.

Our residential assessment coverage includes England, Wales, Northern Ireland and Scotland. Requirements differ between the four nations, so we confirm the applicable route for your project. For site testing, send the postcode so we can confirm availability and arrangements.

Send your project location, a description of the work, current drawings and any planning conditions or building control requests. We will review the information and agree the calculations, reports or tests included in your quotation. Explore our services for an overview.

Include the site address or postcode, project type, number of dwellings, current stage and target date. Send plans, elevations and sections where available, together with construction and building services specifications. Tell us about existing reports and the wording of any planning or building control requirements.

Fees depend on the project, the information available and the agreed assessments. The quotation sets out the scope, deliverables and revision arrangements. Send your drawings and requirements so we can price the work accurately.

We agree the programme before work starts. Timing depends on the project’s size and complexity, the services required and receipt of complete information. Tell us about submission or completion deadlines when you enquire so we can confirm what is achievable.

SAP is the Standard Assessment Procedure used to assess the energy performance of dwellings. Calculations bring together the fabric, glazing, heating, hot water, ventilation and relevant energy systems. Ordellis provides SAP for new builds and assessment support for extensions, conversions and renovations, using the route appropriate to the project.

No. The route depends on the proposed work, existing dwelling and applicable requirements. A heavily glazed extension, for example, may need a comparison calculation rather than a new-build assessment. Send existing and proposed drawings and the building control request so we can confirm the scope.

Design-stage calculations assess the proposed specification and inform design decisions. The as-built assessment uses the final construction, installed systems and required completion evidence. An Energy Performance Certificate records the dwelling’s assessed energy performance. A design-stage report is not the final EPC; completion assessments and EPC arrangements are identified in the agreed scope.

Our Residential EPC service supports new homes and relevant residential conversions. Send the address, project type and final specification so we can confirm the methodology and evidence required. For an existing occupied home, ask us to confirm the appropriate assessment arrangements before booking.

Tell us before relying on an earlier report for the revised design. Changes to insulation, glazing, heating, ventilation, renewables or water fittings can affect the relevant calculations. We will confirm which assessments need updating and whether the revisions are covered by the quotation.

Yes. We can discuss the energy assessment implications for your new-home design. The requirements and assessment method depend on the location, application dates and any transitional arrangements. Share those details and your building control brief. Our Future Homes Standard page explains how to prepare the project information.

Part O addresses overheating in new residential buildings in England. It does not automatically apply to an extension or a building undergoing a change of use. Projects elsewhere in the UK need their applicable requirements or planning brief checked; an overheating assessment may still be requested.

The simplified method checks the design against guidance on solar gains and removing excess heat. TM59 dynamic thermal modelling assesses the building’s thermal response over time. For Part O, the modelling also follows the relevant Approved Document O guidance. We review the design and constraints before agreeing the route.

Provide dimensioned plans, elevations, sections and orientation, plus glazing dimensions and thermal and solar specifications. We also need shading, window opening arrangements and ventilation details. Tell us about noise, security or safety constraints that may limit how openings can be used.

A U-value calculation assesses heat transfer through an element such as a wall, roof or floor. A PSI thermal bridge calculation assesses additional heat transfer at a junction, such as where a wall meets a floor or roof. Both can inform the energy assessment. Send construction build-ups, material specifications and dimensioned junction details for review.

An Energy Statement focuses on the energy strategy and evidence requested by the planning authority. A Sustainability Statement can address broader specified planning requirements, including relevant energy, water and other sustainability measures. Content varies by authority and project, so send the policy or condition wording.

Our Regulation 25 report service brings together the energy reporting information requested by building control. The exact scope needs to be confirmed from its brief. If the request concerns high-efficiency alternative systems in England, that requirement is addressed by Regulation 25A. Send the request so we can identify the relevant regulation and required report.

A photographic evidence report organises the agreed construction photographs and records needed to support the completion assessment. Agree the evidence list before work is covered up, particularly for insulation and junction details. Ask what needs photographing and how each image should identify its dwelling, location and construction stage.

Our Part G Water Calculations assess the specified water use of fittings and relevant appliances against the applicable requirement or planning target. Send the product schedule and manufacturer flow rates, flush volumes, capacities and consumption data. This is a specification-based calculation. Requirements are confirmed for the project’s location and scope.

No. Air tightness testing measures leakage through the building envelope. Extractor fan airflow testing measures the performance of the relevant ventilation outlets. Each needs its own scope and evidence. Send the ventilation specification and building control requirements when requesting a quotation.

Enquire while planning the completion programme so we can agree availability and the relevant readiness checklist. Air testing needs the envelope prepared; fan testing needs the ventilation installation ready; sound insulation testing needs the agreed separating construction and spaces ready. Confirm the site condition before the visit.

We explain the findings and, where included in the scope, discuss design changes, further checks or a repeat assessment or test. Remedial work and retesting arrangements need to be agreed. A report or test result does not guarantee planning permission or building control approval.

Many calculations and reports can be prepared from suitable drawings, specifications and evidence. The information needed depends on the service. Air tightness, extractor fan airflow and sound insulation tests require a site visit; availability and arrangements are confirmed for your postcode.

Email contact@ordellis.co.uk, call 07413 466700, or contact us on WhatsApp. The project enquiry form prepares an email draft for you to review and send from your email app. Check attachments before sending; if you open a plain email link, attach the files yourself. Our hours are Monday–Friday, 7am–7pm UK time; Saturday and Sunday are closed.