What is PHPP (and when do you actually need it)?

A growing number of councils want energy-based net-zero targets that standard SAP can't demonstrate — so they ask for PHPP. Here's what that means, and the difference between PHPP for planning and full Passivhaus certification.

What PHPP is

PHPP — the Passive House Planning Package — is an energy model developed by the Passivhaus Institute. It predicts a building’s space heating demand and total energy use far more reliably than a Part L SAP calculation, because it models the building physics in much greater detail. Post-occupancy studies consistently show PHPP gets close to real-world performance, where SAP can drift.

When you actually need it for planning

Most planning energy conditions are still satisfied with a standard energy statement and a modest renewables contribution. But a wave of authorities have moved to tougher, energy-based net-zero targets — typically a space heating demand of around 15–30 kWh/m²/yr and an Energy Use Intensity (EUI) cap of around 35–40 kWh/m²/yr, covering all the energy a building uses.

SAP wasn’t built to demonstrate those figures, so these councils run their own energy summary tools that are populated from PHPP modelling. If your site is in one of these areas, PHPP is effectively the entry ticket:

PHPP for planning is not Passivhaus certification

This is the bit that trips people up. Using PHPP to demonstrate a planning energy target is not the same as certifying a building to the Passivhaus standard. Certification is a separate, more demanding process — design scrutiny, airtightness targets, certified-product detailing and sign-off — and it’s run by certified Passivhaus designers.

You can (and often must) use PHPP modelling to satisfy these planning policies without pursuing the Passivhaus badge. If you do want the badge as well, you’ll want a certified Passivhaus designer on the team for that side of it.

How this fits your project

The practical upshot: in these areas, fabric performance and u-values matter even more, and the energy statement is a more involved piece of work that’s best started early — before the design is fixed.

We run the PHPP modelling for these planning energy targets and produce the statement in-house, so the modelling and the planning report come from one place. Got a condition that mentions space heating demand, EUI, or an energy summary tool? Send it over and we’ll tell you exactly what’s needed — see our energy statements service for more.

Got a project? Let’s take a look.

Hundreds of clients a year trust us with theirs — big, small, and gloriously complicated. Tell us what you’re up against and we’ll tell you how we’d sort it.