You’ve found your dream plot but how do maximise the land and your design to achieve the best performing building? Gareth Boyd from 2020 Architects has some answers.
Let’s face it, buying a plot to build on isn’t cheap so you will want to make the most of your land to get the best performing building when it comes to energy efficiency and your quality of living.
Taking the time to consider physical and environmental elements will definitely help you to gain the most from your home.
1. Make all the right noises
If there are sources of noise, for example, that are close enough to your plot for you to hear them, then this should inform your design. This isn’t an issue on a rural plot but relates to an urban or busy environment. If you are building close to a noisy road or school, for example, you may consider building bedrooms or quiet spaces away from the sources of noise. Something to factor into the design, if this is the case, is that the mass of a building’s structure is one of the best ways to block noise, so earth sheltered homes, heavy retaining walls and heavy mass construction methods should be considered rather than lighter timber construction techniques.
Steep slopes or dramatic changes in level can create a more complicated build but also have advantages as they can be used to create unique one-off house designs. You can consider living spaces in the upper stories of the house and balconies to create indoor/outdoor spaces and make the most of any views. Bedrooms or private spaces such as bathrooms or snugs might set into the slope at the lowest level where it is quiet and private.
2. The wind factor
If your plot is exposed, which can be an issue on a rural or coastal site, you will need to think about sheltering from the wind. Protecting your house from strong winds is difficult but can be achieved through planting. Solid structures can often lead to more destructive turbulence where the winds swirl over the top of walls damaging any plants at the base of the structure rather than producing a slowing of the wind. When planting to shelter the house think about layers of protection that let the wind through. To be effective, windbreaks must be semi-permeable, ideally filtering 50-60 per cent of the wind to reduce its speed as it passes. Woven screens of willow or hazel are very effective but it can be a skill to produce well. A much simpler solution is woven or extruded plastic netting and is widely available from garden centres.
Wind turbines are a possibility on very windy plots. However, they generally require planning permission, can be noisy and while it slows the wind, it only does so for a very small area. Read more on renewable energy sources for your self-build here.
Although not considered as an obvious problem in our climate with super insulation, cooling our homes is often more of an issue than heating them. A well situated site can use the predominant south west wind direction to provide a more effective natural ventilation for the home. Natural ventilation of any home will rely on the pressure differences between one part of a building and another, or the different pressure between the outside and inside.
3. Consider the orientation for solar gain
When it comes to designing your home, always think about how to maximise solar gain. Solar panels and solar photovoltaics work best on a simple pitched roof of between 35 and 40 degrees facing south or slightly south west. Try to avoid any complexity in the roof, for instance dormer windows or chimneys, as this can create solar shadows on the panels and reduce their efficiency.
Floor-to-ceiling windows and sliding doors are a great option to connect with any views that the plot has to offer. This makes sense but it is worth also considering the effect that all this glass and the subsequent solar gains might have on the temperature levels of your building.
Buildings today are designed to be extremely thermally efficient because of their insulation levels and air tightness so if your floor-to-ceiling windows are on the south or south west side of your building, you’ll find these spaces will heat up significantly. The good news is that your views don’t have to be compromised as long as you consider solar shading of south and west facing windows as well as the proportion and size of these windows. Even with modern ventilation, don’t overlook the benefits of natural, simple flush ventilation to keep the building at a comfortable temperature.
4. Fade from view: think about site access
Consider the orientation of your plot in conjunction with the views and the site access. The ideal plot, if it exists, has access and more public spaces on the northern or eastern sides of the site. This means that large windows, patios and outdoor living spaces can remain private. The views and the most private spaces will be on the southern or western sides of the site, allowing you to benefit from privacy, sunlight and the best aspect. The old adage of a south facing plot is pretty accurate; however, most people aren’t generally in their gardens at midday when a south facing garden is filled with sunlight. Truthfully, a south west facing rear garden is much more useful so that families can enjoy their sun-filled gardens when they return from work and school in the late afternoon.
5. Ground and air source heat pumps
Ground source heat pumps work by heating your home from the small amounts of heat in the ground and as they can be used on most sites it may be worth considering this option. It’s a more cost effective technology if you have a larger site as a bigger area will produce more heat. If you have a smaller site, you can still utilise this technology with a deep bore hole. A client of ours recently installed a ground source heat pump to provide heat energy for a renovation project and while the installation was expensive they were delighted to no longer have to rely on oil or gas. Air source heat pumps are also becoming popular as a more cost effective way to heat self-builds. Air source heat pumps use the same technology as ground source but use the small amount of heat in the air to create warmth in the home.