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Remote / Desktop

Desktop Heat Loss Calculation — from drawings, no site visit needed

MIS 3005-D room-by-room heat loss produced remotely from your floor plans and measurements. Every assumption documented. From £150. UK-wide.

25,000+ heat loss calculations across the founder's career · MIS 3005-D + CIBSE · next-day delivery once inputs are confirmed.

Send your drawings for review See a sample pack
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Not sure your drawings are enough? Send them over. We tell you what is missing before you book — nothing is confirmed until you approve scope and price.

How it works

Three steps, no site visit

The desktop route is built for homeowners gathering independent evidence, for installer teams with measured inputs already in hand, and for anyone where a site visit would add cost and delay without adding accuracy.

Step 1

Send what you have

Floor plans (architect, estate-agent, or hand-drawn), room dimensions, window sizes, construction type, insulation details. We review the inputs and tell you what is usable and what is missing — before you book.

Step 2

Scope and price confirmed

Once inputs are complete, we confirm scope, assumptions that will be documented, and the final price. Nothing is booked until you approve — no vague quoting, no surprises.

Step 3

MIS 3005-D output, next day

Room-by-room heat loss, U-values, ventilation rates, and every assumption made visible. Delivered through the Vertex Portal the next working day once inputs are confirmed.

Inputs we need

What to send us

These are the inputs that make a desktop calculation properly usable for MCS-aligned heat pump sizing. You do not need all of them — send what you have and we will flag the gaps.

Floor plans

Any usable plan works

  • Architect drawings or building regulation plans
  • Estate-agent or property-portal floor plans
  • Hand-drawn sketches with measurements marked
  • Separate plans per floor, ideally with a scale
Measurements

Room-by-room dimensions

  • Length and width of each room
  • Ceiling heights (flag any sloped ceilings)
  • Window and external door sizes per room
  • Doorway positions and orientations where possible
Property fabric

Construction and insulation

  • Wall type (cavity, solid brick, timber frame, stone)
  • Cavity fill status if known
  • Loft insulation depth, floor insulation if known
  • Glazing type (single, double, triple)
  • Approximate build date or extension history
Heating detail

Current system and targets

  • Existing heat source and fuel
  • Radiator sizes where emitter assessment is needed
  • Underfloor heating zones and build-up where relevant
  • Flow-temperature preference for the new system
Send your drawings for review See pricing Heat loss overview Heat loss inputs guide
Straight answer

When desktop works — and when it doesn't

We would rather talk you out of a desktop calculation than produce one that isn't reliable. Here's how the call is made.

Desktop is fine

Good candidates for the desktop route

  • Recent builds with architect drawings and documented fabric
  • Properties with complete floor plans and known construction type
  • Homeowners with an up-to-date EPC and reliable room measurements
  • Installer teams that have already captured measured inputs
  • Quotes where the heat pump design is not constrained by plant-room space
Visit is better

When we'll recommend a site visit

  • Incomplete or inconsistent drawings
  • Older properties with unknown cavity fill or mixed extension fabric
  • Unclear loft or floor insulation status
  • Plant-room or cylinder-space layout is a design constraint
  • Anything where assumptions would carry material sizing risk

If a site visit would materially improve accuracy, we say so before you book. The ASHP survey + heat loss package covers both (£350, save £50 vs booking separately) — see pricing.

Output

What's in the desktop heat loss pack

The same MIS 3005-D output as a site-visit calculation — just produced from drawings rather than site measurements. Every assumption is documented so any installer can design from it without re-opening inputs.

Calculation

Room-by-room heat loss

  • Per-room W/m² and total kW values
  • U-values per building element
  • Ventilation rates by room
  • Design temperatures documented
Assumptions

Every input made visible

  • Construction assumptions listed against source evidence
  • Insulation levels flagged where estimated
  • Glazing and air-tightness assumptions documented
  • Any gaps or caveats called out, not hidden
Delivery

Portal pack, same quality as site-based

  • Delivered through the Vertex Portal
  • PDF pack branded with your logo where requested
  • Installer handoff-ready structure
  • Usable by any MCS installer for design and sign-off
Who books this

Who the desktop route is built for

Homeowners

Independent evidence before you pick an installer

Commission an MIS 3005-D heat loss from your own drawings. Take it to as many installers as you like — they all quote from the same documented facts, so quotes are genuinely comparable. More for homeowners.

Installer teams

When you have measured inputs already

Your surveyors captured room data on site, you just need the calculation and documented assumptions. Send us the inputs — we produce the pack next day. Get installer pricing.

Architects and designers

Design-stage heat loss from plans

Early-stage heat pump sizing from drawings. Useful when specifying plant-room layouts and emitter strategies before a building exists to visit.

FAQ

Frequently asked questions

Yes. If you can provide floor plans, room dimensions, window sizes, construction type and insulation details, we can produce a full MIS 3005-D heat loss calculation remotely. Every assumption is documented so any installer can design from it. If your inputs won't support a reliable desktop calc, we will tell you before you book — nothing is confirmed until you approve scope.

£150, the same as our site-data heat loss. Larger properties (200–300m²: +£100; 300–400m²: +£200; each extra 100m²: +£100) carry the same uplifts as a standard calculation. Full pricing on the pricing page.

Next working day once inputs are confirmed and the job is booked. The input-review stage before booking is usually same-day — send drawings in the morning and we'll normally respond the same afternoon with what is usable and what is missing.

Yes. The output is produced to MIS 3005-D and CIBSE guidelines, with every assumption documented clearly. Any MCS-registered installer can use it for design and sign-off. If an installer has specific format requirements, let us know — the output is usable across the mainstream heat pump design tools.

Yes — that's exactly what it is built for. An independent heat loss calculation means every installer quotes from the same documented facts, so you can compare quotes on a like-for-like basis rather than on different assumptions.

We review inputs before quoting. If gaps are fixable (extra measurements, photos of construction details), we'll tell you exactly what to send. If the gaps would force unsafe assumptions, we'll recommend a site visit instead rather than produce an unreliable calculation.

Next steps

Related services and resources

Send drawings for review Heat loss overview Homeowner option Pricing Sample pack Heat loss inputs guide Heat loss calculations guide UK heat loss calculator ASHP survey Installer pricing