Q: What is a SAP calculation and do I need one?
A:
SAP stands for Standard Assessment Procedure. It’s the official method used in Scotland to measure the energy performance of new homes and major alterations.
You’ll typically need a SAP calculation if your project involves:
• A new-build house
• A conversion (e.g. barn to home)
• A large extension with over 25% glazing
SAP calculations are used to:
• Demonstrate compliance with Section 6 – Energy of the Building Standards
• Produce your EPC (Energy Performance Certificate)
• Confirm that your design meets energy efficiency targets
We arrange the SAP calculations for you as part of the building warrant process.
Q: What is a U-value and why does it matter?
A:
A U-value measures how well a building element (like a wall or roof) retains heat. The lower the number, the better the insulation.
Typical U-value targets in Scotland:
• Walls: 0.18 W/m²K
• Roofs: 0.13 W/m²K
• Floors: 0.15 W/m²K
• Windows/doors: 1.4 – 1.6 W/m²K
We calculate and report U-values for each relevant part of your design and include them in your building warrant submission.
Q: Who carries out the SAP calculations — and do I need to organise it?
A:
No need — we take care of it. Houz Design will:
• Identify if a SAP assessment is required
• Work with a trusted SAP assessor on your behalf
• Supply them with all necessary drawings and specs
• Receive the SAP report and EPC certificate
• Submit all documents with your warrant application
We’ll ensure your energy compliance is handled efficiently and without hassle.
Q: How much do SAP calculations and U-value reports cost?
A:
Energy assessment costs vary depending on the size and type of project. As a guide:
• U-value calculations only: £250 – £300
• Full SAP & EPC for a new build or large extension: £300 – £400+
We’ll obtain a clear quote before proceeding and invoice you directly once agreed. No work is instructed without your approval.
Q: Can better U-values or SAP scores reduce my heating bills?
A:
Absolutely. A more energy-efficient design:
• Reduces heat loss
• Lowers your long-term energy bills
• Improves comfort in your home
• May qualify for certain grants or funding (e.g. Home Energy Scotland)
We can also advise on smart upgrades like thicker insulation, air source heat pumps, or MVHR systems to improve performance even further.
Q: What happens if my design doesn’t pass the energy assessment?
A:
If your design doesn’t initially meet the required energy standard:
• We’ll work with the assessor to understand the issue
• Recommend design tweaks or specification upgrades (e.g. better insulation, lower U-value windows, etc.)
• Update your drawings and re-check compliance
We aim to get it right the first time — but we’re here to adjust and support until it’s approved.