Energy efficient architectural design principles
Updated: Nov 27, 2020
Whether you’re hunting for the perfect section or ready to build your dream home, there are several key design principles that will improve the energy efficiency of your home for years to come. As the architectural energy experts, we’ve pulled together our top tips for warmer, dryer, healthier homes, with little power bills and lower impact on your surrounding environment.
Harnessing the sun
The best site for a warm, energy efficient home gets plenty of sun, particularly from the north, and is sheltered from prevailing winds. On clear, winter days the sun sends around 500 Watts of heat through each square metre of unshaded north-facing window.
A home designed to harness the sun's free warmth:
Is placed on the sunniest part of the section
Is oriented to face the sun, with the main living areas to the north and service areas such as garages and toilets on the south side
Has plenty of insulation to trap in the free heat from the sun
Uses thermal mass - like a concrete floor, exposed to the sun so it soaks up heat during the day and releases it when temperatures drop at night
Has appropriately sized and positioned windows - moderately large on the north-facing side of the house, smaller on the east and west sides, and smallest on the south side
Has properly designed overhangs over northerly windows to limit summer sun whilst allowing plenty of sun in during winter. Overhangs don’t work well on east and west sides as the sun is too low – deciduous trees and movable shades or louvers are better options here.
The more complex a home's shape is, the more floor, wall and ceiling area it has to lose heat through. Simple house designs - for example compact rectangular shapes and multi-level homes - have less external surface area, so are easier and cheaper to keep warm. Smaller houses are also cheaper to build, easier to heat and use a lot less energy.
Good design, materials and construction will enable your home to retain heat for your comfort and lower heating bills. The important factors are:
High levels of insulation in ceiling, walls and underfloor, well in excess of minimum building code requirements
Ensuring insulation is installed carefully without any gaps, tucks or folds, to the New Zealand insulation standard NZS 4246
Insulating any concrete floor on the ground - both underneath and around the perimeter
Minimising plumbing and electrical services inside external wall cavities, as they compromise the insulation and airtightness in affected cavities
Double glazing with insulating frames and low-E glass
Air locks at external entrances to keep out cold draughts
Building airtightness combined with controllable ventilation provisions, like a heat recovery ventilation system.
Effective ventilation helps to remove moisture and maintain air quality. In summer, it’s the key to keeping your house cool and comfortable. The key things to know about ventilation:
Most houses can be well ventilated with adequately sized and located windows that can be opened
Room layout and window placement can be designed to enable effective cross-ventilation, which is good for summer cooling
In highly insulated and airtight homes, a well-designed and installed heat recovery ventilation system can provide good ventilation and further reduce heat loss
Properly sized and located extractor fans are essential for removing moisture from wet areas such as the kitchen, bathrooms and laundry.
Ready to start designing your energy efficient home? Talk to the experts at Minimal Design today and enjoy the benefits of a warmer, dryer, eco-friendly home tomorrow. Well, it takes a bit longer than that, but you get the gist.