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Why Spruce Is Our Default Heat Pump Design Platform
At Heat Loss Hub, Spruce is our preferred heat pump design platform for many of the projects we undertake. It brings property surveying, room-by-room heat loss calculations, heating-system design and technical documentation into a connected workflow.
- 11 min read
- Published 18 June 2026
- By Phil · Heat Loss Hub
Clients sometimes ask what sits behind the calculations, radiator schedules and system designs we produce. The answer is often Spruce, although the software is only part of the process.
After years of working with heating systems, I’ve learned that good design depends on reliable information, sound engineering decisions and clear communication between the designer and installer.
Spruce helps organise that work, but it doesn’t replace the experience needed to make those decisions.
This article explains why we use Spruce, what it can do and where the designer remains responsible.
IN ONE PARAGRAPH
Spruce connects surveying, heat loss, heating-system design and project documentation within a single platform. We prefer it because information can move between those stages without unnecessary duplication. However, Heat Loss Hub remains responsible for assessing the building information and completing the technical work included in each commission.
This is an independent, unpaid account of software we use professionally. Heat Loss Hub is not Spruce’s software vendor or official support provider, and we don’t receive a referral commission for recommending it.
What Is Spruce Heat Pump Design Software?
Spruce is a UK-focused software platform developed for heat-pump installation businesses and heating designers.
It brings several stages of a heat-pump project together, including:
- Property surveys and floor-plan creation.
- Room-by-room heat loss calculations.
- Radiator and heating-emitter assessments.
- Heat-pump and hot-water system design.
- Pipework drawings and technical documentation.
- Customer estimates, proposals and installation paperwork.
- Quality management and handover processes.
Rather than treating surveying, heat loss and system design as unrelated tasks, Spruce allows relevant project information to be carried between them.
For installers managing multiple jobs, that can reduce repeated administration and make project information easier to follow.
Heat Loss Hub uses the technical design elements of Spruce for appropriate projects. We don’t sell Spruce subscriptions, and customers who want to purchase or evaluate the software should visit Spruce’s official website for current features, demonstrations and pricing.
Why Heat Loss Hub Uses Spruce
One of the main reasons I prefer Spruce is the continuity between surveying a building and developing its heating-system design.
Traditionally, heating design could involve site notes, separate drawings, spreadsheets, calculation software and manually prepared reports.
Every time information moves between systems, there’s another opportunity for measurements or assumptions to be entered incorrectly.
Spruce reduces some of that duplication by keeping relevant project information connected.
For Heat Loss Hub, its main advantages are:
- A connected workflow: Property information can progress from surveying into heat loss and system design.
- Flexible surveying: Projects can begin with existing plans, measurements or appropriate digital surveying methods.
- Structured calculations: Room-by-room heating requirements can be reviewed alongside the underlying building information.
- Design continuity: Heat loss results can inform emitter assessment and subsequent equipment selection.
- Professional documentation: Reports and drawings can be prepared from the project information.
That doesn’t make Spruce universally better than every alternative.
It means the platform suits how we prefer to organise many of our design projects, particularly where we’re collaborating with installation businesses.
From Property Survey to Heat Pump Design
An accurate heat loss calculation starts with reliable information about the property.
Spruce supports several ways of collecting that information.
For a new build or major renovation, architectural drawings may provide a suitable starting point.
For an existing home, we might use available floor plans, homeowner measurements, photographs, manual surveying or an on-site assessment.
Where appropriate, a compatible device can use LiDAR to capture room geometry.
LiDAR can be particularly useful for recording complicated spaces, but it isn’t automatically more accurate than every other measuring method. Measurements still need checking where accuracy matters.
More importantly, accurate dimensions don’t establish what’s inside a wall.
A room scan can’t confirm concealed insulation, identify every construction alteration or establish whether an assumed U-value is appropriate.
Those details require separate evidence and professional assessment.
Once the property information has been established, Spruce can use it as the basis for room-by-room heat loss calculations and the subsequent design.
For a more detailed explanation, read Spruce Survey & Design Tool: How the Installer Workflow Works.
What Can Spruce Help Us Produce?
Spruce supports several important elements of a heat-pump design.
These include room-by-room heat loss reports, radiator and emitter assessments, heat-pump selection, domestic hot-water considerations, pipework drawings and supporting technical documentation.
However, there’s an important distinction between what the software can produce and what a customer has commissioned Heat Loss Hub to deliver.
A heat loss calculation establishes the heating requirements of the property.
It doesn’t automatically include radiator replacements, heat-pump selection, pipework specifications or a complete system design.
Those additional elements require further information and an appropriately scoped commission.
For a complete design project, the work may progress from establishing room heat losses to assessing existing emitters, determining suitable flow temperatures and selecting equipment.
Technical drawings and supporting documentation can then form part of the agreed deliverables.
For calculation-only work, the output is more limited.
We confirm the scope before proceeding, so the customer or installer understands exactly what is included.
Our separate guide explains how the Spruce Heat Loss Calculator works and how its results support the next design stages.
Where Software Stops and Engineering Judgement Begins
This is the most important part of the process.
Spruce can perform calculations, organise information and help produce professional design documentation. But it can only work with the information and assumptions entered into the project.
Software doesn’t turn an uncertain building assumption into a verified fact.
Consider an older property with solid masonry walls.
The designer needs to decide which construction information is reliable, whether further investigation is justified and which U-values are appropriate.
The software can calculate the heat loss using those values, but it cannot independently confirm every concealed construction detail.
The same principle applies throughout heating-system design.
Someone still needs to establish:
- Whether the room dimensions and building-fabric information are credible.
- Whether ventilation and infiltration assumptions are appropriate.
- Whether existing radiators can meet the calculated room loads.
- What heating flow temperature offers a sensible balance between efficiency and installation cost.
- Whether the selected heat pump can meet the design load at the required outdoor and water temperatures.
- Whether existing pipework and hydraulic arrangements are suitable.
- Whether the final documentation accurately represents the proposed installation.
These decisions have practical consequences.
An incorrectly assumed wall construction can distort the heat loss. An inadequate radiator can leave a room cold. An overlooked pipework restriction can prevent the required water flow.
The software makes the calculations easier to manage, but the designer remains responsible for checking whether the proposed system makes engineering sense.
Similarly, software-generated documentation may support MCS-related design requirements, but it doesn’t automatically establish that a complete installation meets every applicable standard.
Spruce provides the tools. The designer provides the judgement. Both matter.
Example — How a Spruce Design Project Comes Together
Consider a hypothetical three-bedroom house where the homeowner wants to replace an existing gas boiler with an air source heat pump.
The project begins with available drawings, photographs, construction information and details of the existing radiators.
A typical design process might look like this:
| Project stage | Design work |
|---|---|
| Property information | Check measurements, construction and insulation assumptions |
| Heat loss calculation | Establish whole-house and room-by-room heating requirements |
| System design | Assess emitters, design temperatures and suitable heat-pump options |
| Documentation | Review and prepare the agreed technical reports and drawings |
This is an illustrative workflow, not a claimed completed Heat Loss Hub project.
Suppose the results show that most radiators are suitable at the proposed flow temperature, but two rooms require additional emitter output.
The designer can assess replacement options and consider their effect on the operating temperature.
The heat pump must then be checked against its actual manufacturer performance at the property’s design conditions.
Spruce helps connect these stages so the design can develop from the same building information.
The finished deliverables are then checked against the agreed scope before being issued.
Spruce Beyond Heat Loss and System Design
Spruce has developed into more than a standalone heat loss calculator.
Its wider platform supports customer enquiries, early estimates, property surveys, proposals, installation documentation, handover and quality-management processes.
For an installation business, having these functions within a connected platform can reduce some of the administration involved in moving a project from first enquiry to completed installation.
However, the wider software capabilities shouldn’t be confused with Heat Loss Hub’s services.
We’re an independent heating-design consultancy, not an installation management or software subscription provider.
The work we undertake depends on what has been agreed for the individual project.
Because software platforms change regularly, the best place to check current Spruce features and subscription options is Spruce’s own website.
Is Spruce the Only Design Software We Use?
No. Spruce is our default platform for many projects, but it’s not the only design software we work with.
Heat Loss Hub can also work with Heat Engineer where appropriate to the project and the installer’s existing workflow.
Both platforms provide tools for heat loss calculations and heating-system design, although their broader capabilities and workflows differ.
For installer partnerships, flexibility can be important.
If an installation business already has an established process, there may be little benefit in forcing every project into a different software environment.
Our priority is producing a sound design using reliable information and an effective working process.
For a detailed comparison, read Spruce vs Heat Engineer for Heat Pump Design.
Already Using Spruce? Heat Loss Hub Can Support Your Design Work
Many heat-pump installers already have the practical skills needed to survey properties, manage customers and complete installations.
The challenge is often finding enough time for the technical work between the survey and installation.
Room-by-room calculations, radiator assessments, equipment selection, hydraulic considerations and documentation all require office time.
As installation enquiries increase, that workload can become a bottleneck.
Heat Loss Hub can provide additional technical design capacity for installers already using Spruce.
Depending on the agreed arrangement, an installer might continue managing the customer, conducting the survey and preparing the installation quotation, while HLH undertakes specified calculation or system-design work.
Where suitable project access and working arrangements are established, that support can fit within the installer’s existing Spruce workflow.
The installer retains the customer relationship and responsibility for the installation, while we complete our agreed technical scope.
This can work for an occasional project, additional capacity during busy periods or a more regular design-support arrangement.
The important part is establishing clear responsibilities, information requirements and deliverables.
Already using Spruce but need more design capacity?
Read Outsourced Heat Pump Design in Spruce: How It Works to see how we can support your installation business without unnecessarily duplicating your existing workflow.
What Does This Mean for Homeowners?
If you’re planning a heat-pump installation, you don’t need to choose the design software yourself.
What matters is whether the heating requirements have been established correctly and whether the proposed system has been designed around your property.
You should be able to understand the room-by-room heat loss, the reasoning behind radiator changes, the proposed operating temperatures and why a particular heat pump has been selected.
The reports should also make clear what has been calculated and what assumptions have been used.
At Heat Loss Hub, we use appropriate professional design tools to support that work, independently of equipment sales and installation commissions.
If you’d like a design carried out before committing to an installer, explore our Independent Heat Pump Design Service.
Frequently Asked Questions About Spruce
No. Heat Loss Hub is an independent heating-design consultancy. We use Spruce professionally but don’t sell software licences or provide official Spruce subscriptions or support. Visit Spruce for current software information.
No. Spruce supports different methods of establishing property dimensions, including existing drawings, floor plans, manual measurements and LiDAR. The appropriate surveying approach depends on the property and the available information. Accurate construction assumptions remain essential regardless of how dimensions are collected.
Software can support calculations and documentation aligned with applicable MCS requirements, but compliance depends on the actual design, reliable inputs, correct technical decisions and the relevant installation responsibilities. A software-generated report alone doesn’t certify an installation.
Yes. Heat Loss Hub can support installers who already use Spruce by undertaking agreed technical design work. The arrangement can be tailored to the installer’s surveying process, project information and requirements. See our Outsourced Spruce Design guide for more information.
For heat-pump installers: If you already use Spruce and need additional technical capacity, explore Outsourced Heat Pump Design in Spruce.
For homeowners: If you’re planning a heat-pump installation and want independent engineering advice, explore Independent Heat Pump Design.
Heat Loss Hub — Independent heating design, supported by professional tools and experienced engineering judgement.
CONTENTS
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Every Heat Loss Hub design pack — calculations, emitter schedule, drawings — comes out of the workflow described here.
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FOR INSTALLERS
You are reading about our design platform.
If you fit heat pumps and would rather spend evenings on site than in design software, we produce MCS-ready calculations and full system designs in Spruce and issue them in your own name.
Outsourced heat loss calculations
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