Whether you're planning a renovation or building from scratch, it’s important to consider how the homeowner lives in conjunction with home performance and aesthetics to create a home that's as functional as it is beautiful.
To understand the strategies for balancing performance and design, we spoke to Roger Borland, director of Borland Architecture, who shares expert tips on how to achieve the perfect balance.
As certified Passive House designers, Borland Architecture utilise the principles of passive house in all their designs, whether existing or new.
“This includes airtightness, high levels of consistent insulation throughout the building envelope, high-quality windows and doors, heat recovery ventilation systems, and elimination of thermal bridges.”
This high performance house by Borland Architecture shows how careful planning and orientation increases home performance.
The most effective ways to enhance energy efficiency without compromising on design
Enhancing a home's energy efficiency starts with a holistic approach that marries design with performance. The first port of call is to gain an understanding of how the occupants will use the space, shares Borland.
“At Borland Architecture, we firstly prioritise the orientation of the home to maximise natural light, heat gain and ventilation. This includes positioning living areas to capture the warmth of the winter sun while shading them in summer. We then integrate appropriately sized high-performance windows and doors with consistent insulation and airtightness throughout the building envelope to ensure thermal comfort without sacrificing aesthetic appeal.”
Balancing aesthetic appeal with functional performance is central to Borland Architecture’s design philosophy. This balance is achieved by thoroughly understanding clients' priorities from the outset. Carefully exploring each family member's unique needs and preferences during the briefing stage, ensures that functionality drives and enhances the aesthetics of the space.
“For example, we may discover that the mother likes to get up early, make a coffee, and read in the early morning sunshine. This insight enables us to place a window seat in the morning sun near the kitchen.”
The design of a home is shaped by the unique lifestyles and functional requirements of each family member, serving as the foundation upon which the aesthetic is built, but even with an understanding of how the family currently operates, it’s important to anticipate potential shifts in family dynamics. For example, children may eventually leave home, or a grandparent with limited mobility might move in. Can the space's functionality be designed to accommodate these possibilities from the beginning?
“If planned correctly, the home design can incorporate flexibility, avoiding future detriment to the aesthetics,” shares Borland.
The placement and size of windows is an essential design tool for improving a home's performance.
1. Window Design
Window design plays a crucial role in energy efficiency, as windows can be up to 20 times less energy efficient than the walls they are installed in due to their thin profile and lack of insulation, says Borland.
Optimising window placement is essential to maximise energy savings, and in the southern hemisphere, positioning windows on the north side of the home and designing eaves that block high summer sun while allowing low winter sun to penetrate can create a net energy gain through passive solar heating.
“We avoid large openings on the east and west, where solar gain is difficult to control, and provides heat gain predictability,” says Borland. “And limiting windows on the south, where they will only provide a net loss in solar energy, is also important.”
Once the glazing has been oriented correctly, the windows needs to be as close to the performance level of the walls they are situated in as possible.
“This requires the use of double or triple glazing with low-E glass, as the cavities between the glazing panes have low conductive gases that act as thermal insulators, limiting heat loss and unwanted ultraviolet light,” says Borland. “The window frames, typically the weakest thermal part of any window assembly, should be selected from materials that are low in thermal conductivity, such as wood or uPVC.”
If the client prefers aluminium, it must be thermally broken, meaning there is an insulated core separating the inside of the frame from the outside.
“In our homes, we go one step further and, where possible, detail the window frames so they are largely built into the walls with insulation overlapping. This improves the otherwise poor performance of the frames and brings their performance closer to the wall assembly.”
Preventing drafts in the design is one of the easiest ways to increase efficiency.
Insulated windows and walls are key to high performance.
2. Eliminate drafts
Any singular upgrade alters the physics of a building, resulting in a knock-on effect. For example, adding insulation could cause moisture to condense within the wall assembly itself, reducing the insulation's performance but also keeping the wall structure damp, eventually leading to failure and encouraging mould growth, which could impact the respiratory systems of occupants.
“A much better solution is to comprehensively improve the building, firstly through thermal modelling to know where the risks are, and then designing and building solutions with active controls built in for weather-tightness, moisture, ventilation, airtightness, insulation, and structural integrity.”
In existing buildings, eliminating drafts is always the first point of call, says Borland.
“Ideally, this is done through the use of a blower door test, which pressurises the home so that air leaks can easily be identified and fixed. If this isn’t possible, starting with installing good air seals around windows and doors, and finding and filling in gaps in the structure will have a huge impact on comfort, as drafts can make our bodies feel a greater level of discomfort than temperature alone.”
3. Boost performance with insulation
Insulation is crucial for maintaining consistent indoor temperatures and reducing energy consumption, as it prevents heat loss through conduction.
“It also plays a significant role in soundproofing, enhancing the comfort and privacy of a home. Properly installed insulation without penetrations, well-detailed around all building junctions, combined with airtight construction, eliminates drafts and cold spots, contributes to both performance and occupant comfort.”
For existing homes, even if the house has had insulation installed it’s important to check for gaps. This can be done using a thermal camera, which will often show gaps where services have been installed, under raised floors, and in eaves spaces.
A HRV system is the first port of call when it comes to smart systems in the home.
4. Incorporate smart home technologies
Smart home technologies are revolutionising the way we manage and optimise home performance, and the most critical smart home technology to improve home performance is a Heat Recovery Ventilation system (HRV), says Borland.
“This system is always active, removing contaminated air, moisture, VOCs, viruses, and allergens, and replacing them with fresh filtered air that has been mixed with captured energy. It acts as the lungs of the home while saving up to 90% of heating and cooling energy, making it the most critical smart technology you can install in our opinion.”
Borland Architecture also installs renewable energy control systems, aligned with batteries and electric vehicles, to smooth out energy demand, reducing reliance on the grid and allowing for energy self-sufficiency.
5. Ventilation is key
Ensuring proper ventilation is key to maintaining good indoor air quality, but it cannot be adequately provided by relying on occupants to open windows and doors. Passive House design uses a heat recovery ventilation system (HRV) to efficiently manage fresh air intake and stale air exhaust, maintaining healthy indoor conditions.
“This system also ensures the ideal air mixture at all times, avoiding spikes in CO2, especially in bedrooms, which we know has detrimental impacts on our quality of sleep.”
