Building Green

With UK renewable energy capacity surpassing fossil fuels for the first time in 2019 1 , and government plans to ban mains gas central heating systems in new homes by 2025 2 , sustainable and energy efficient construction is fast becoming a necessity. Yet, despite all the renewable and ‘green’ technologies available, implementing and using them correctly is not without its challenges.

According to Imperial College London, in the past five years the amount of renewable capacity has tripled while the use of fossils fuels has fallen by a third 3 ; a milestone that some would have considered impossible just a few years ago. Earlier this year, the UK Government announced plans to ban gas boilers from all new homes in 2025 2 , in a bid to lower CO2 gas emissions.

Whilst these are both positive and important steps towards a more sustainable future for all, there is still a long way to go for all buildings to implement and, most importantly, use and maintain green technologies efficiently and effectively.

When it comes to designing buildings that incorporate environmentally friendly technology, solar panels on the roof are the least of it. There are many ways that architects can use computer modelling, up-to-date materials and tech to ensure that their buildings retain a low-carbon legacy.

Thermal insulation is an extremely effective green technology; it is possible to make significant energy savings by improving the thermal insulation values of a building. Achieving optimum levels requires careful calculation. Too much insulation can lead to overheating, especially in summer which can lead to using artificial cooling systems, negating the environmental benefits. Fortunately, the ideal amount of insulation, ventilation and heat exchange a building requires can be accurately calculated using energy modelling software.

Equipment such as ground-source heat pumps, which extract heat from the ground beneath a property, and airsource heat pumps, which are powered by electricity (a renewable source in contrast to natural gas), also help a building maintain its green credentials.

Architects today even have the capability to control the amount of fresh air flowing into a building; CO 2 monitors in air extract ducts can be used to reduce the volume of fresh air coming into a building at times of low occupancy. LED lighting and Building Management Systems (BMS) fall into the green technology category too, as LED lights use significantly less energy than traditional light sources, and BMSs allow for heating and lighting to be switched off when they are not needed.

The World Green Building Trends 2016 Smart Market Report reveals that the demand for green buildings is doubling every three years 4 . Yet, installing green technologies does pose a number of challenges, and there are considerations that people must take into account.

First of all, there is the cost. Many people believe sustainable building to be expensive and they are partly correct. The initial costs of using green and renewable technologies is often much higher than standard technologies, however rewards further down the line in terms of energy savings, are significant. Payback periods vary for each project, ranging from 18 months to 20 years in extreme cases, but engineers can forecast the payback for each technology through modelling the effects of various green technologies. Overall, the complete lifecycle cost of using green technologies is considerably cheaper than standard technologies.

And it doesn’t just boil down to money, there is also the bigger issue of the environmental cost to consider. As guardians of our planet, we have a responsibility to future generations to protect and maintain our world. Significantly reducing CO 2 emissions will have an even greater impact on all our lives, as well as saving money.

Another key challenge to the adaptation of green technologies is the available space. Air source heat pumps, for example, tend to be larger and require much more air space to operate correctly, which can prove challenging in smaller buildings or buildings with limited space. Green technologies also require more commissioning and maintenance than standard services, meaning people must be prepared to undertake this to ensure optimal efficiency of the technology.

The last, and perhaps hardest challenge that green technologies pose, is a mindset change. It is important to understand that green technologies sometimes come with compromises, compared to standard installations, which may affect quality of life.

For example, ground source heat pumps tend to operate at lower temperatures than gas powered heating systems and will take longer to heat the building up to temperature. Hot water provided by storage heaters takes a long time to warm up and requires a recharge period once the hot water has been used, compared with a gas fired boiler which provides constant hot water. However, by using a professional engineer to calculate your water loads and usage, you can have the right size hot water tank, low water-use shower heads and taps installed to suit your individual needs.

Simon Green, Director of Green Building Design Consultants, comments “Designing green buildings is not a straightforward process. Using an engineer to help guide you and accurately calculate the potential savings is a necessity, as is being fully on board with the new technologies and how to maintain them and your own lifestyle, in order to see optimal results. However, when it is done well, the results are seriously impressive, as we showed with a recent exemplar project. An 1850’s 6-bedroom semi-detached house was renovated, resulting in more than an 80% reduction in CO2 emissions, proving that even Victorian housing has a huge energy saving potential.”

With electrical energy costs averaging three and a half times those of natural gas, only through planning ahead and having the correct design, installation, commissioning and maintenance of your green technologies, will you be able to lower your CO2 emissions, reduce energy usage and save money.

SOLAR, SO GOOD

Humans have long harnessed the sun for power, but it’s only recently we’ve been able to convert its energy into electricity.

On a bright sunny day in July in 1913, the great and the good of Egyptian society gathered together to witness a scientific miracle – a water irrigation plant run on solar power.

This wasn’t solar power as we know it; carefully placed, high shine metal plates were set out in the sun, and the heat generated from them created enough steam power to operate an irrigation pump for water to get from the Nile to the fields.

As incredible as it seemed at the time, it was in the same vein as humans had been using the sun for millennia; in the 2nd century BC, Archimedes is said to have set fire to enemy ships using mirrors.

It wasn’t until 1954 when the first photovoltaic cells were developed in America that could convert energy from the sun into electricity to power everyday objects.

Starting at 4% efficiency and getting as high as 11%, these first solar panels were based on a patent filed in 1908, and they haven’t changed much today.