Should I opt to build low energy or aim for Passive House Standard?

LOW ENERGY V'S PASSIVHAUS: WHICH IS RIGHT FOR YOUR SELF-BUILD?

When planning a self-build, energy performance is often a top priority. Whether it’s cutting carbon emissions, lowering running costs, or creating a comfortable home that works in harmony with the environment, designing for energy efficiency makes sense.

At Allan Corfield Architects, many of our clients ask the same question early in their self-build journey:

“Should I aim for a low-energy home or build to the full Passivhaus standard?”

It’s a great question—and the answer depends on your goals, budget, and how far you want to push performance. In this article, we’ll explore the key differences, benefits, and considerations to help you make an informed decision.

WHAT IS A LOW ENERGY HOME?

A low-energy home typically goes well beyond current Building Regulations regarding energy performance. It’s designed with good insulation, airtight construction, high thermal performance windows, efficient heating systems (often a heat pump), and smart ventilation—usually a Mechanical Ventilation with Heat Recovery (MVHR) system.

These homes are often built using principles inspired by Passivhaus but without strictly following the certification process or hitting all the required benchmarks.  You can find out more about designing and building a low-energy home here.

Passivhaus (or Passive House) is a rigorous energy standard developed in Germany that’s gaining momentum across the UK. It’s focused on five core principles:

• Excellent thermal insulation

• High-performance windows and doors

• Airtight construction

• MVHR for healthy, efficient ventilation

• Minimal thermal bridging

The result is a home that maintains a stable, comfortable temperature year-round with minimal heating or cooling. Certification is carried out by a third party and requires precise energy modelling and on-site testing.  You can learn more about Passivhaus here. 

WHY CHOOSE A LOW-ENERGY HOME?

A low-energy home is a great option if you want to:

• Improve energy efficiency without the extra cost of certification and don't want to follow standardised criteria. 

• Keep more design flexibility 

• Achieve a good level of comfort and low running costs

• Work with a builder who may not have Passivhaus experience

Many of our clients find this route strikes the right balance between performance and cost, especially if working within a tight budget.

WHY CHOOSE A PASSIVHAUS?

Passivhaus is the gold standard for comfort, performance, and carbon reduction. You might choose this route if:

• You prioritise excellent internal comfort and a healthy living environment

• You want the lowest possible energy bills and emissions

• You value independent verification of performance

• You want to avoid the risk of “performance gap” (i.e. what’s designed vs what’s built)

• You’re aiming for a home that will exceed Future Homes Standards and be resilient for decades

• You want to future-proof your property and maximise resale value. 

It’s especially worth considering if you are building in a colder part of the UK or if your goal is to create a home that will perform exactly as designed.

WHAT ABOUT COSTS?

There’s no getting around it—building to Passivhaus does cost more upfront. Typically, you might see 2-4% from low energy to PH standard or 4-8% from low energy approach. However, this is often offset by:

• Lower running costs (heating bills can be reduced by up to 90%)

• Smaller or no heating systems needed, depending on design and location. 

• Improved long-term durability and property value

And importantly, as more UK suppliers and builders become experienced in Passivhaus, costs are coming down.

FUTUREPROOFING

With Scotland set to introduce a Passive House equivalent standard in 2028, our in-house PH Consultant, Iga Pancynza, recommends the importance of  futureproofing your home. If you are building now with low-energy design principles but not pursuing certification, you could risk reduced property value once the new standard becomes mandatory. Certification not only demonstrates your home’s quality and performance, but it also protects your investment. You’ve already committed to building better, so why not certify and fully realise the benefits of your sustainable build?

OUR RECOMMENDATION

If your goal is to build a high-quality, efficient, and comfortable home, either route can be successful. The choice really comes down to:

• Your budget

• Your performance targets

• Your appetite for certification and precision

At Allan Corfield Architects, we take a performance-first approach to every self-build project—whether you're aiming for a low-energy home or targeting full Passivhaus certification. Our team integrates fabric first design principles from the earliest stages, working closely with clients, energy consultants, and contractors to ensure that your goals are met in practice as well as on paper.

We offer in-house expertise in modern methods of construction and provide a comprehensive service for your self – build including in-house Passive House Consultancy and, where required, collaborate with certified Passivhaus Designers and consultants to guide projects through detailed PHPP modelling and certification. 

From concept design to completion, we help you navigate the technical requirements, identify cost-effective solutions, and with the help of PHPP software (link to article on PHPP software), we can ensure that your new home is designed to deliver exceptional comfort, performance, and long-term value.

If you would like to learn more and discuss your potential low-energy or Passivhaus designs, click on the link below to book a consultation with one of our experts.