Structural Calculations for Solar Panels
Building control ready · PI insured · worked remotely
For standard residential (domestic) properties with a pitched roof. Flat roofs and large-scale installs need a separate assessment — ask us for a quote.
Before solar panels go on a roof, building control needs to know the existing structure can safely carry the extra load. Calcs-Online provides the structural calculations that prove it — a building-control-ready report, prepared remotely by structural engineers and backed by professional indemnity insurance. Order online, choose your date, and send us six details.
- 9,000+ projects since 2012
- 100% approval, or your fee refunded
- Structural engineers
- PI insured
Roof, rafters and load path checked for your panel array
Your solar panel calculations
One roof, one calculation pack, ready for building control.
See the price, then order online
The price you pick below covers the complete structural calculation for your panel array. No survey, no quote forms — add it straight to your basket.
Roof & rafter load assessment
We check your existing roof structure — rafter size, spacing and condition — against the added dead, live, wind and snow loads of the panels, and verify the load path down to the walls.
Building control ready, PI insured
A calculation report prepared specifically to satisfy building control, backed by professional indemnity insurance and a 100% approval rate across 9,000+ projects since 2012. If building control does not approve it, we refund the fee.
What do solar panel structural calculations include?
Everything building control needs to sign off the extra load on your roof:
- Roof structure & rafter assessment — size, spacing and adequacy of the existing rafters
- Panel load calculations — dead, live, wind and snow loads for your specific array
- Capacity verification — confirming the existing roof can safely carry the panels
- Load path check — how the added load transfers safely down to the supporting walls
- Building-control-ready report — the calculation pack, prepared for building control
- Installer / contractor pack — clear output your installer can work from
What we need from you
Six details — no drawings needed for a standard pitched roof:
- Your postcode
- Roof type (e.g. pitched, tiled)
- Rafter size
- Rafter spacing
- Photos of the loft
- Your approved solar quotation
Flat roof, commercial building or unusual structure?
The prices on this page cover standard residential (domestic) pitched roofs. Flat roofs, non-standard rooflines and large-scale or ground-mount arrays need a separate assessment — get in touch and we’ll quote it individually. For a commercial or industrial building, show us the project and we will tell you whether we can help, or point you to someone who can.
Ask us for a quote →Choose your date
Same calculation pack, same engineers: each option shows its own price, so pick the one that suits your install.
Secure checkout. After you order we’ll ask for six details (below) — we begin once we have everything we need.
Why choose Calcs-Online for your solar panel calculations?
PI insured
Every calculation pack is produced by structural engineers and backed by professional indemnity insurance — the reassurance building control and installers look for.
Building control ready
Prepared specifically to meet building regulations, with a 100% approval rate on 9,000+ projects since 2012, and the fee refunded if yours is not approved.
Worked remotely
Your six details and loft photos are all we need, wherever you are in the UK.
Your price first
You see the price before you order. No survey costs.
A date to suit you
Pick the option that suits your install date; the price is shown against each one.
Building-control approval
Building control has approved every set of calculations Calcs-Online has issued; if yours were refused, we would refund the fee.
Our step-by-step process
Choose your date and add to basket
Pick the option that suits your install and check out online.
Send your six details
After checkout we’ll ask for your postcode, roof type, rafter size and spacing, loft photos, and approved quotation.
Structural assessment
Our engineers assess the roof structure and rafters against the panel loads, and verify the load path to the walls.
Building-control-ready report delivered
Your calculation pack arrives on the date you chose — ready for building control, with an installer pack included.
Submit to building control
Send the pack with your application. If building control ask about the calculations, pass the question to us.
FAQs
Frequently asked questions
Do I need structural calculations to install solar panels?
In most cases, yes — building control needs evidence that your existing roof can safely carry the added weight and wind loading of the panels. Our calculations provide exactly that, ready for sign-off.
Will my calculations pass building control?
Yes. Every set of calculations we have issued has been approved by building control, across 9,000+ projects since 2012, and if yours are not approved, we refund the fee.
Do you need to visit my property?
No. Calcs-Online works remotely, from your six details and loft photos, and does not visit site. Working this way keeps the cost down.
What exactly do you need from me?
Six things: your postcode, roof type, rafter size, rafter spacing, photos of the loft, and your approved solar quotation. For a standard pitched roof that’s all we need — no architectural drawings required.
How much does it cost and when will I get it?
Each option and its price, including VAT, is shown in the picker above. Pick the one that suits your install.
Is this for residential or commercial properties?
This service is for standard residential (domestic) properties with a pitched roof — houses, bungalows and similar homes. Large-scale or ground-mount solar arrays need a separate structural assessment; contact us and we’ll quote it individually. For a commercial or industrial building, show us the project and we will tell you whether we can help, or point you to someone who can.
What if my roof is flat or an unusual structure?
Flat roofs and non-standard structures need a separate assessment. Get in touch and we’ll quote it individually.
Are you insured?
Yes — every calculation pack is produced by structural engineers and backed by professional indemnity insurance, for your and your installer’s peace of mind.
Get your solar panels signed off
Structural calculations for solar panel installations — building control ready, PI insured, worked remotely. Choose your date below.