A heat pump project is easier to plan when the property has been assessed before the system is specified. For installers, that means clearer heat-loss inputs and a better understanding of the existing heating system. For social-housing teams, it means seeing what varies from home to home before a programme moves into delivery. Thermcal provides independent, property-level retrofit assessments, room-by-room heat-loss calculations and heat-pump capacity assessments to support that work.

Start with the home, not the heat pump

A heat pump is one part of a wider heating system. Its performance and suitability depend on the heat demand of the building, the way heat is delivered around the rooms, hot-water requirements and the condition of the existing installation. A product choice made before those details are understood can leave important design questions to be resolved late in the process.

An assessment gives the installer or housing delivery team a clearer starting point. It records relevant property information, considers the existing fabric and heating arrangements, and identifies matters that may affect the proposed works. The aim is not to make every home look the same. It is to establish what is known, identify what still needs checked and provide useful inputs for the next decision.

Why room-by-room heat loss matters

A whole-house heat-demand figure is useful, but it does not show how that demand is distributed between rooms. Room-by-room heat-loss calculations help identify the heating output needed in each space under the agreed design conditions. They can then inform discussions about heat-pump capacity and whether the existing or proposed heat emitters are suitable for the intended operating conditions.

The calculations are only as reliable as their inputs. Dimensions, exposed surfaces, construction details, insulation, glazing and ventilation assumptions all matter. Where information is missing or uncertain, that should be made visible so the project team can decide whether to verify it, use an agreed assumption or obtain further evidence.

A heat-loss assessment is an important design input; it is not, by itself, a complete system design. The installing contractor remains responsible for the final system design, equipment selection, installation and commissioning.

Look at the whole retrofit picture

Heat loss is central to heat-pump sizing, but a retrofit assessment should also consider the wider home. Relevant items may include insulation and glazing, ventilation, airtightness information, the current boiler and controls, radiators or underfloor heating, hot-water provision, electrical or external-unit constraints, and any renewable technologies already present or being considered.

This broader view helps teams understand whether preparatory work, further investigation or a change to the proposed scope should be considered. It can also put the heating proposal in context with EPC or SAP information where that work is included in the commission. An energy assessment should not be mistaken for a structural survey or a hazardous-materials inspection; those require their own competent specialists where needed.

NISEP grants and upcoming heat pump funding in Northern Ireland

People searching for NISEP grants, a NISEP heat-pump grant, Northern Ireland heat-pump funding or a Stormont heat-pump grant need to check which scheme is actually open and who can apply. NISEP is an existing programme. The 2026/27 scheme year runs from 1 April 2026 to 31 March 2027, and the available measures, eligibility rules and remaining funding depend on the individual scheme and delivery provider. An Assembly answer describes local NISEP support for whole-house retrofit measures, including insulation and heat pumps, with solar PV and battery storage also supported in some arrangements.

The Department for the Economy is also developing a Domestic Energy Efficiency and Low Carbon Heat support programme. In September 2026, the Economy Minister said the Department would consult during the year on scheme design and funding options. Earlier Assembly answers described development of a future scheme intended to replace NISEP. At the time of writing, final grant values, eligibility rules and application dates have not been confirmed. Searches such as “Northern Ireland heat-pump grant 2027”, “Stormont energy grants” and “low-carbon heating support NI” should therefore be treated as enquiries about a developing policy, not proof that a new grant is open.

A separate scheme is the Department for Communities’ Warm Healthy Homes Fund, which is expected to become the Department’s main fuel-poverty intervention for eligible low-income owner-occupied and private-rented homes from April 2027, replacing the Affordable Warmth Scheme. Its proposed approach is whole-house and fabric-first. It is designed for private-sector homes, so social-housing providers should not assume that it will fund work to Housing Executive or housing-association stock. Social housing retrofit funding follows separate landlord, department and procurement routes. The Housing Executive’s existing energy-efficiency and thermal-improvement programme is a separate public-sector route; in February 2026, the Communities Minister told the Assembly that £41.75 million was planned for this work in 2026/27.

For homeowners, installers and housing providers alike, the practical step is to check current eligibility and scheme guidance before promising grant support. A property-level retrofit assessment and heat-loss calculation can still help establish the home’s needs while funding rules are being developed.

For the latest position, check the official NISEP 2026/27 scheme information, the Department for the Economy’s low-carbon heat support updates and the Department for Communities’ Warm Healthy Homes Fund information.

Make property-by-property planning work at programme scale

Social-housing programmes often involve homes with different ages, layouts, heating systems and records. A consistent assessment process can help a provider and its delivery partners compare properties on a like-for-like basis while keeping each home’s specific findings visible.

When assessments are completed early enough to influence planning, the team can identify missing information, access needs and design questions before an installation date is fixed. That can support clearer work scopes, more informed resident communication and better coordination between surveyors, installers and programme managers. It does not remove the need for site checks or design decisions by the delivery team, but it gives those decisions a better evidence base.

For installers, independent assessment support can also help manage the survey and calculation workload when several enquiries or properties are moving at once. The scope, required outputs, data format and programme timings should be agreed at the outset so the work fits the installer’s process.

What a Thermcal assessment can include

Thermcal can agree a property-level package to suit the project. Depending on the commission, this may include a retrofit assessment, room-by-room heat-loss calculations, a heat-pump capacity assessment, review of the existing heating and hot-water arrangements, and a written summary of findings and items to confirm.

Where required and separately included, the assessment can be coordinated with relevant EPC, SAP, RdSAP or other building-energy work. The report can distinguish confirmed information from assumptions and outstanding queries, so the installer or housing team can see where a decision is ready to progress and where more evidence is needed.

Thermcal provides assessment and calculation support. It does not supply or install heat pumps. The installer retains responsibility for the final system design and delivery.

Help the assessment answer the right questions

The most useful assessment starts with a clear brief. It helps to provide available floor plans, elevations or previous surveys, EPC records, details of past improvements, the current heating and hot-water system, and any known constraints on access or installation. If the work is part of a wider programme, an outline schedule and the team’s preferred report format can help align the outputs with the delivery process.

Not every home will have complete records. That is common in existing-property work. The key is to record the evidence available, identify gaps and agree how those gaps should be handled before the results are used for equipment selection or programme decisions.

Plan the next step before installation

Whether you need heat-pump survey support for one home or are planning a social-housing retrofit programme, contact Gareth Chambers at Thermcal to agree the property scope, report outputs and programme dates. Thermcal provides independent assessment and calculation support to installers, housing providers, housing associations and retrofit delivery teams across Northern Ireland. Get in touch at gareth@thermcal.co.uk or 07841 573626, or visit thermcal.co.uk.