This is the first installment in a series of posts aimed at educating customers who are interested in new construction, with a focus on implementing sustainable design and building practices. This series will cover nearly every aspect associated with new construction, starting with siting and design and moving through the building phases sequentially.
Building a new house can be daunting. There are thousands of decisions that need to be made at every phase of construction. However, before a hammer can hit a nail – or even before a shovel strikes the dirt – the actual structure needs to be designed. If the proper amount of attention isn’t paid during this early stage of the process, the entire project can be marred by inefficiency and result in an end product that doesn’t meet one’s expectations – both aesthetically and energy efficiency-wise. This part of the process can be varied, both in how it is carried out, as well as who is included. Regardless of this, as the future owner of your dream home, there are certain things you should be discussing with your designer.
Many of the following design features need to be settled on up front, and with a little foresight, you can have a sustainable home that is a high performing energy-mizer as well! Adhering to some or all of the following principles can lead to significantly lower operational costs, higher resale value, increased comfort, as well as a durable structure that will last for generations.
The single largest thing you can do to both save money and play a positive role environmentally is to build a smaller house. Building a house is a very personal endeavor, and it is easy to get carried away adding spare bedrooms, etc. Remember, every extra square foot of space that you include in your house will need to be heated, cooled, ventilated, cleaned, maintained, and taxed. Even if you can afford it, it’s best to avoid the temptation of a large house.
Smaller homes are more cost effective for a variety of reasons:
- Require less resources to initially build
- Require less land
- They are easier to condition (e.g. heat/cool)
A simpler shape has many benefits over a convoluted one. While this may come down to your aesthetic preferences, it is always sensible to design your house by avoiding superfluous features such as unneeded dormers, valleys, and Garrison-style overhangs (where the second floor is cantilevered over the first). The reasons to avoid these kinds of features are numerous, but the main ones are:
- They utilize more materials and are more labor intensive, therefore
- They have higher costs
- These features are harder to detail in terms of making them airtight and flashed properly to keep out bulk moisture (such as precipitation)
- In general, they are less resource efficient
If your building lot allows some flexibility, there are some basic principles that should be followed with regards to how your building is oriented. In general, it is best to keep the long axis of your house south, southwest, or southeast.
The reasons for this are twofold:
1.Solar Panels: depending on your roof layout it gives you a great plane for installing solar panels that are optimally oriented to maximize their power output. There is a reasonable amount of flexibility with regards to tilt (in this case, roof pitch) as well as orientation.
- A tilt within +/- 10 degrees of the optimal tilt angle only decreases capacity by less than 2%.
- Solar panels that are oriented +/- 30 degrees from true south only have decreased output by about 4%.
2.Comfort: namely, daylighting and optimized passive solar gain. More daylighting will not only decrease your reliance on artificial light, but can also be a great mood booster; while the passive solar gain can manifest itself by decreasing heating bills in the winter (while properly sized overhangs can inhibit its heating effects during the summer – but more on that later).
Shading and Wind Breaks:
Shading and wind breaks can take many appearances, but most commonly are found in the form of trees. The benefits of shading are relatively straightforward. In the heat of summer it is much more pleasant in the shade – away from direct sunlight. You can utilize properly placed trees for just this! Not only do trees provide nice spots for summer picnics, but they can shade your house and help keep it cooler in the summer. And BONUS! If they are deciduous (that is they lose their leaves in the winter) they let that wonderful winter sun in through your windows, thereby passively heating your home (as was mentioned in the previous paragraph).
Though easier to forget about, wind breaks are equally as important as proper shading. A building that is exposed to an excessive amount of wind is susceptible to some very insidious things – the worst of which is air infiltration.
Wind blowing against a wall creates an area of high pressure on the windward side and negative pressures on the leeward side. Furthermore, this can be exacerbated by building corners, porches, and other features that act as dams – more reasons to simplify that building shape!! All of this leads to an increased amount of air infiltration, which is chief among causes of heat loss and high heating bills.
All of this can be mitigated with a properly placed windbreak. These windbreaks can consist of:
- Other buildings
- And even topographic features such as hillocks.
Evergreens are a great choice for wind deflection.
It’s best not to put the cart ahead of the horse. In this case, it’s best to have a solid plan when building a new home. Being thoughtful in the design phase of construction especially regarding
- House size
- Layout and house shape
- Orientation of your home on your building lot
- Shading and wind breaks
will give you a foundation to make sure your new home will perform well down the road. These often overlooked (or at best, minimally considered) details can save you considerable amounts of money over the life of your new home, as well as make it more comfortable and durable!