Frequently Asked Questions

Here's the workflow in a nutshell:

1. Set up your project - add the project name, plot numbers, and link to your assessor.
2. Take photos on site - the app walks you through each Appendix B section so you know exactly what to photograph. GPS, date, and time are embedded automatically.
3. Generate your report - one tap creates a professional, formatted report with all your evidence organised by compliance section.
4. Share with your assessor - send the report directly from the app. If your assessor has an Assessor Portal account, the report and photos land straight in their dashboard. Either way, your email app opens with a link to the report's page for them - press send, and they can open the PDF and download the photo zip. The link doesn't expire: send again and it opens the new version, and it only stops if you send the plot to a different assessor or delete the report.

That's it. No spreadsheets, no Word documents, no chasing metadata. The whole process takes minutes instead of hours.

You can use Buildsnapper to capture photos and generate reports without linking to an assessor. But to send reports directly from the app, you'll need to add one.

If your assessor already uses Buildsnapper Assessor or the Assessor Portal, linking up is quick - just search for them in the app. If they don't use Buildsnapper yet, enter their name and email address instead. Either way, they get a link to the report's page in your email.

There are two costs to think about. First, the assessor's fee - a typical OCDEA package covering design-stage SAP, as-built SAP, and the BREL report ranges from a few hundred pounds per plot on a simple new build to several thousand for a larger development, depending on complexity and how clean the evidence is.

Second, the tools and time your builders spend capturing photographic evidence on site. With Buildsnapper, that's £6.67-7.99 per month per device - compared to the unbillable hours typically lost organising photos from WhatsApp, email, and phone galleries.

The biggest hidden cost is poor evidence. Missed photos mean opening walls back up, delayed handovers, or a more conservative as-built SAP that knocks your Energy Performance Certificate down a band. Getting evidence right first time saves far more than it costs.

For a new-build dwelling, you need an OCDEA (On Construction Domestic Energy Assessor). A plain DEA doesn't have the qualification to sign off Part L on a new build.

The letters look similar but the qualifications don't. Every OCDEA is also a DEA; not every DEA is an OCDEA. Check your assessor is accredited for on-construction work before you start a plot - accreditation bodies (Elmhurst Energy, Sava, Quidos, ECMK) all maintain public registers you can search.

For existing homes being sold, rented, or post-renovation, a standard DEA producing an EPC is fine. For new builds specifically, it has to be an OCDEA.

Appendix B splits photographic evidence by construction stage. You'll typically need clear photos of:

1. Foundations, DPC, and ground-floor insulation - before the slab goes in
2. External walls and cavity-wall insulation - while the cavities are still open
3. Floor and floor insulation - before the screed or final flooring
4. Roof and loft insulation - before the ceiling or roof covering closes it up
5. Windows, doors, and glazing - installation and sealing
6. Airtightness measures - membranes, tapes, and sealed service penetrations
7. Heating, hot water, and ventilation plant - installation and commissioning
8. Renewable and low-carbon technologies - solar PV, heat pumps, and similar

Each photo needs GPS coordinates, a date, and a timestamp embedded in its metadata. Without them, your assessor can't confirm when or where the photo was taken - and the evidence is effectively useless.

Part L isn't a single event - it runs alongside the whole construction process.

• Design-stage SAP calculation: a few days once the design is finalised and before construction begins
• Photographic evidence capture: ongoing through construction, as each stage gets buried or covered up
• As-built SAP and BREL report: typically a few days to a week after construction completes and all commissioning certificates are in

A clean evidence package speeds the whole thing up. A messy one drags the final stage out for weeks as the assessor chases missing photos, commissioning data, and airtightness results.

Yes - as long as location services are on so the photos are GPS-tagged, and you organise them by plot and by Appendix B section.

Where people come unstuck:

• Location turned off when the photo was taken - GPS can't be added later
• Multiple plots' photos mixed into one zip - the assessor has to sort it
• Photos without timestamps (sometimes stripped by messaging apps like WhatsApp)
• Missing a stage because you didn't know it was needed

A purpose-built evidence app like Buildsnapper removes these risks. GPS and timestamps are embedded automatically; photos are organised by plot and by Appendix B section as you go.

Building Control won't sign off the dwelling, which blocks handover and occupation. In practice, your OCDEA will flag missing or weak evidence before sign-off so you can fix it - but fixing means one of three options:

1. Supply equivalent evidence if it exists elsewhere (rare)
2. Open the work back up to photograph what was missed (expensive)
3. Accept a more conservative as-built SAP, which can mean a worse EPC band for the finished home

The fix is always more expensive than capturing evidence right first time. For a volume housebuilder, the compounded cost across a development can run into tens of thousands of pounds.

Building Control doesn't formally approve individual apps or tools. What it accepts is the evidence itself - organised photos with verifiable GPS, dates, and timestamps, mapped to the Appendix B sections, assessed by an OCDEA.

Buildsnapper's report format was designed in collaboration with BREL assessors to meet exactly those requirements. In practice, reports generated through Buildsnapper are accepted by Building Control bodies and OCDEAs across the UK. We always recommend showing your assessor a sample report at the start of a project to confirm it meets their expectations.

The Future Homes Standard is the UK Government's transition to make new homes zero-carbon-ready - published in March 2026 and in force from 24 March 2027. The headline shifts:

• No new gas boilers in new-build dwellings once fully in force
• Low-carbon heating (typically heat pumps) as the default
• Tighter fabric standards - better walls, roofs, floors, and windows
• Stricter airtightness expectations
• More photographic evidence per plot, reviewed with sharper scrutiny by OCDEAs

In practice: more photos, better organised, faster reviewed. The evidence bar is rising at the same time as the construction standards. For a deeper dive, see our Ultimate Guide to Part L Compliance.

Buildsnapper is the core mobile app for builders. It walks you through exactly what to photograph at each stage of a new build, tags every photo with GPS, date, and time, and generates a professional report your assessor will actually accept - all in one tap.

Available on iOS and Android. From £6.67/month with a 14-day free trial.

Buildsnapper Manager is for site managers and project managers who need oversight across multiple builds. Every project that lists your email address shows up with its plots, and each plot's row shows how many of its six sections are done - a tick when all six are - without opening it. Open a plot for its sections, its latest report and which assessor it went to.

You don't capture evidence with the Manager app. Your builders do that with Buildsnapper on their devices. Manager gives you visibility into their progress without needing to be on every site.

Available on iOS and Android. £39.99/year with a 14-day free trial.

Buildsnapper Assessor is the free companion app for energy assessors (DEAs). When your builders send their Part L evidence through Buildsnapper, it arrives in the Assessor app structured, complete, and ready to review.

If you've got an Assessor Portal account, the PDF report and a zip of every photo land straight in your dashboard. Otherwise, the builder emails you a link to the report's page, where you open the PDF and download the photo zip. The link doesn't expire, and it only stops if the builder sends the plot to a different assessor or deletes the report. Either way, you get the formatted report and every photo as its own file, still tagged with where and when it was taken. Completely free - no trial, no catch.

Available on iOS and Android.

The Assessor Portal is a web dashboard for assessors who want to manage everything from their computer. You can set up projects on behalf of clients, review evidence, buy licences in bulk, and add your own branding to every report your builders generate.

It's free to use alongside the Assessor app. Log in to the Assessor Portal.

Without the Portal, each report arrives as a link in an email from the builder. It works, but it means digging through your inbox for the right link, and managing everything yourself.

With the Portal, every report and photo zip from your builders is stored in one dashboard for as long as the builder's report and account remain active. (For guaranteed long-term retention, the paid Photo Evidence Archive keeps a tamper-proof copy for 15 years.) You can:

• Access all client reports and photos any time, in one list
• Set up projects on behalf of your builders
• Buy and manage licences in bulk (with volume discounts)
• Add your own branding to every report your builders generate

It's completely free, so there's no reason not to. Apply for a free account - we check each one by hand, usually within one or two working days.

Here's the full breakdown:

• Buildsnapper (for builders) - £7.99/month or £79.99/year (works out at £6.67/month). Both plans come with a 14-day free trial.
• Buildsnapper Manager (for site managers) - £39.99/year with a 14-day free trial.
• Buildsnapper Assessor (for energy assessors) - completely free, always.
• Assessor Portal (web dashboard) - free to use alongside the Assessor app.

Your free trial starts when you subscribe through the App Store or Google Play, using the payment method already on your store account. Cancel any time before the 14 days are up and you won't be charged.

Yes. As a new user, you get the first 14 days free on both the monthly (£7.99/month) and the annual (£79.99/year) plans. The trial starts when you subscribe through your app store and continues automatically as a paid subscription when it ends - cancel any time during the trial and you won't be charged.

Buildsnapper works differently to platforms that charge per user. Here's how it breaks down:

• One licence = one device. Your subscription covers a single account on a single phone or tablet. Photos and evidence are stored locally on that device.
• No user limits. The device can be passed around on site between as many people as you like. There's no per-user charge - it's tied to the device, not the person holding it.
• One device can handle multiple plots. A single phone can capture evidence for as many plots as you need. However, once you start collecting evidence for a plot on a particular device, that device must continue to be used for that plot. Plot evidence can't be moved to a different device mid-way through.
• Projects can be shared. The project itself can be shared across multiple devices. So different team members can work on different plots within the same project, each on their own device - they just can't swap plots between devices.
• Reports and photos go to the cloud. Although photos are stored locally while you're capturing, once you generate and send a report, the PDF and a zip of every photo are uploaded. If your assessor has an Assessor Portal account, both land in their dashboard. Otherwise, they open both from the link in your email.

In practice, you keep the same phone with each plot from start to finish. Take photos as you go, generate the report when you're ready, and send it off. Simple as that.

We're currently working on a pro version of the app that will allow plot evidence to be shared across devices.

Yes. The licence is tied to the device, not to a specific person. Anyone on site can pick up the phone, take photos, and add evidence to a plot. There's no per-user limit.

The important thing to know is that once you start collecting evidence for a plot on a device, that device needs to stick with that plot. You can't start a plot on one phone and continue it on another. A single device can handle multiple plots - but each plot stays on the device it started on.

If you need different team members working on different plots at the same time, each device needs its own licence. They can all share the same project - just not the same plots.

We're working on a pro version that will allow plot evidence to be shared across devices in future.

Once you've captured all the evidence for a plot, you generate the report with one tap. The app compiles everything - photos, GPS data, dates, times - into a professional PDF report organised by Appendix B section.

When you send the report, the PDF and a zip of every photo are uploaded to the cloud. If your assessor has an Assessor Portal account, both land straight in their dashboard. If they don't, they open both from the link in your email, which works until you send the plot to a different assessor or delete the report.

After that, the device is free to start capturing evidence for the next plot. Everything stays safely in the cloud.

Yes. Buildsnapper works on both phones and tablets - iOS and Android. Just bear in mind that the licence is per device, so a tablet and a phone would need separate licences if you want to use both at the same time.

No problem. Add them in the app with their name and email address and send the report as normal. They get a link to the report's page, where they open the PDF and download the photo zip - no account needed.

They can also apply for a free Assessor account from that page. It makes their life easier too, and there's no cost to them.

Yes. There's an example report built into the app so you can see exactly what the finished product looks like - layout, structure, and how the photos sit within each section. New accounts also get a demo project: the finished plot that report was made from, to look through before you take your first photo.

The photos in the example are Elmhurst Energy's examples, marked "Sample". Your actual report will contain the real evidence from your site.

Top tip: have a quick chat with your assessor before you start, so you both agree on what photos they need.

You can also view a sample report on our homepage.

There's no single "official" format for Part L photo evidence. We designed the Buildsnapper report format in collaboration with BREL assessors - the industry professionals who assess building regulations compliance for energy and ventilation.

That said, every assessor has their own preferences. We'd always recommend showing your assessor a sample report at the start of a project so you're both on the same page.

Evidence needs its location, so Buildsnapper won't import a gallery photo without one - it tells you the photo has no location data. Usually location services were off when the photo was taken, or the location was stripped when it was sent through another app.

On Android, if you only let Buildsnapper see some of your photos, Android can hold the location back - allow access to all photos in Settings. The easiest fix: take the photo in Buildsnapper itself, which always records the location.

This is an optional section for any extra documents your assessor might want alongside the photo evidence - for example, energy performance calculations (SAP results), sound test results, or air tightness certificates.

It's not a required part of Appendix B, so you don't have to fill it in. Check with your assessor whether they'd like anything included. If you do add documents, they need to be in PDF format.

Your photos and generated reports are stored locally on your phone or tablet while you're working. Everything else - project names, plot details, assessor information - is stored securely on our servers.

When you send a report, the PDF and a zip of every photo are uploaded to the cloud. If your assessor has a Portal account, both are available in their dashboard for as long as the report and your account remain active. Otherwise, they open both from the link in your email, which works until you send the plot to a different assessor or delete the report.

If you've already sent the report to your assessor, the PDF and photo zip are safe - either in their Portal dashboard (for as long as the report and your account remain active) or from the link in your email. Your assessor can still access everything.

For photos you haven't sent yet, it depends on your backups. Since version 2.0, every photo you take in Buildsnapper also leaves a copy, with its location and time, in your phone's gallery (as long as you've let it add photos there). If iCloud Photos or Google Photos was backing up your gallery, those copies are safe. On an iPhone, an iCloud backup also carries the app's own photos. On Android, Google's app backup doesn't include them - they're too big for it - so the gallery copies are what count.

If none of those backups were switched on and the report hasn't been sent, unfortunately the photos can't be recovered - they're stored locally on the device. This is why we always recommend keeping your phone's gallery backed up to iCloud Photos or Google Photos.

We're working on a pro version of the app that will include cloud storage, which would remove this concern entirely.

Usually, yes. iPhone to iPhone: Apple's phone-to-phone transfer or an iCloud backup carries the app's photos across. Android to Android: use the phone-to-phone transfer (cable or Wi-Fi) when you set up the new phone - Google's cloud backup alone doesn't carry the photos.

Either way, open Buildsnapper on the new phone and check your photos are all there before you wipe, sell or hand back the old one.

We're working on a pro version of the app with cloud storage, which will make device upgrades seamless.