Paul Testa

Paul Testa

Architect Paul is the director of HEM Architects and a specialist in low-energy design. HEM Architects are well-versed in designing sustainable, energy-efficient new builds and extension schemes. He has also just completed an eco retrofit to his family home.

He taught the technology course for the MArch in Architecture at Sheffield University, and is a tutor for the Sustainable Architectural Studies Masters course. 

Latest articles by

exterior of self build with timber cladding and blue windows

I'm an architect and here's why eco homes need to pass the Blower Door Test

By Paul Testa published

Architect Paul Testa explains why new build homes need to take a Blower Door Test to measure the airtightness of their property and meet building regulations

A thermal image of a house

What is a thermal bridge and how can it cause significant damage to your home?

By Paul Testa published

We answer the question 'what is a thermal bridge' and discover ways to design them out of your property to keep your home warm and cosy

air sealing system

What is airtightness and why does it matter?

By Tim Pullen, Paul Testa last updated

Just what is airtightness? In this guide we explain why it is a key ingredient in creating an energy efficient home, what is it and how it is measured

two men calculating u-values in house

What is a U-value and how are they calculated?

By Paul Testa published

Just what is a U-value? With achieving the highest possible levels of sustainability and performance for our homes now more important than ever, understanding this term is vital for all homeowners

Self build country home, morning mist

What is Part Z? How building regulations proposal could affect self builders

By Paul Testa last updated

Architect Paul Testa explains how the proposed Part Z could work in lowering carbon emissions from new buildings

this retrofit home met enerPHit plus standards

EnerPHit: The Ultimate Guide to Passivhaus Standard Retrofit

By Paul Testa last updated

Meeting the EnerPHit standard is the peak achievement for retrofitting an existing property to be energy efficient. This is what you need to know

Worker Spraying Blown Fiberglass Insulation between Attic Trusses

Is Liz Truss's energy price freeze only a short-term fix for a long-term problem?

By Paul Testa published

Architect Paul Testa examines criticism of the Energy Price Guarantee amid calls for a national insulation strategy to be urgently introduced

Wooden frame of a residential house construction photographed from the ground floor looking up through the roof trusses at a blue sky

Embodied carbon: Why new construction proposals could impact self builders

By Paul Testa published

Architect Paul Testa explains the problem of embodied carbon within construction and why self builders should be aware of potential new limits

a house which has been retrofitted

Why do we Still Not Have a National Retrofit Strategy?

By Paul Testa last updated

It feels crazy to be in a position that a national retrofit strategy isn’t in place and working at full capacity, says Paul Testa

Insulate Britain

We Need to Talk About Insulate Britain’s Demands for our Homes

By Paul Testa published

As Insulate Britain makes its voice heard, retrofit expert Paul Testa outlines that efficient insulation can only work when it’s part of a whole house plan