Gorgeous Green House

The Renovation Journey of a 1940’s ‘Traditional’ to 2015 ‘Contemporary, Green & Gorgeous’


2 Comments

The Idiot’s Guide to SANS 10400. (Applicable to all new builds, not just green ones!)

Glandiolus dalenii flowering this month

Safety used to be the primary criteria for glazing. It’s got a lot more complicated!

Until very recently our building standards mainly focused on strength, stability, safety and the like.  Your windows could be as large (or small) as you liked, as long as you could show they wouldn’t kill people (too easily). You could put in as much lighting, heating and air conditioning as your heart desired and you could heat your water in any way you cared to (just about).  Rainwater that accumulated on your roof and other hard services as well as your waste water just needed to be routed into the municipal storm water systems.

This has all changed significantly under the recently released SANS (South African National Standards) 10400 regulations.  And lots of professionals in the building industry have been caught on the hop!  The domino effect has been delays in plans being approved, construction pushed out and in some instances halted, while everyone gets ‘up to speed’, certificated and educated.  It seems that our government’s invitations to consultative processes were largely ignored so the new standards were implemented with little fanfare.  It is only now that non-compliance is being identified by the authorities that architects, designers, builders and suppliers of goods and services to the industry are fast tracking their knowledge and skills.   These standards are not a South African invention.  In fact much of the science has been lifted from all the good work done in the rest of the world.  We are actually lagging far behind and currently only have 30 Green Star Rated buildings to brag about.  Our Green Building Council http://www.gbcsa.org.za has only been in existence since 2007.

So What is SANS 10400 all about? 

Before I go any further with this post I must get my disclaimer in!  I am not an expert on SANS 10400 and can only share the lessons I have learned with my own build.  The standards themselves are complicated and require lengthy calculations. I have no plan to get into the nitty gritties of such, nor will I address the standards in a comprehensive way.  My intention is to rather provide a general overview of what the key challenges are and offer some suggestions on navigating some of the worst bits.

As we are all aware we have an energy crisis in this country, because we’ve felt the pain of power cuts for protracted periods.  We also have a water crisis and infrastructure problems but we haven’t had rolling water outages (yet) or major life taking floods due to overburdened storm water systems so we are still somewhat complacent. By the way, these problems are not unique to SA, they are of concern all over the planet. So essentially, the new regulations have been implemented to mitigate these problems.

Basically, these regulations are forcing all new builds and alterations to be a lot greener than before.  Whether you are interested in building green or not, you won’t get your plans approved/passed until they achieve the minimum requirements.   SANS 10400 needs to be read in conjunction with SANS 204 and they cover everything about buildings from safety, glazing, lighting, ventilation structural design etc. etc.  I will be focusing on some of the issues contained in the Environmental Sustainability and Energy Usage sections (parts X and XA).

These standards may look very onerous but when one considers that 17% of our national energy is used in residential buildings and 10% in commercial ones it is clear that we need to be building a bit smarter.  It’s also quite sobering to learn that the buildings globally are responsible for a third of CO2 emissions either in their construction or lifespan.   The standards are also very complicated.  South Africa is divided into different climatic zones (not always with sound logic is seems) as Durban (annual temperature range 16°  – 28° C) and Mooi River ( 0.6°C  – 24.2°C)  are in the same zone.  There are different standards for different building use and even different calculations to be applied for rooms relating to the different directions they face.          

MY TOP TIPS

Qualified Professional

First and foremost you are going to need your intended architect and/or engineer to have been accredited by the Building Control Authority.  Do not assume this is already so.  Many professionals have attended various presentations etc. but unless you find their name on this website:  http://www.buildingcontrol.co.za/page34.html  they are not ‘deemed competent’ and your plans will not be approved.  If they are this far behind the starting blocks you are in for a protracted process of referrals (declined plans).  Best find someone who is qualified to do all the tricky calculations that are going to need to be done and generally up to speed on building green.

Windows

If your windows are large you may have to install fixed awnings

Glazing/fenestration/windows are always significant in building for reasons of comfort and aesthetics.  If yours represent more than 15% of your wall area things are going to get complicated because you will potentially take more energy off the grid to cool and heat your building.  Bottom line, you won’t be able to install standard single glazed windows.   To put in larger windows, calculations will have to be done to justify the fenestration plans.  These are based not only on the surface area but the type of glazing and framing proposed, your climactic zone etc. The overall aim is for your windows to let in as little heat as possible in summer (because you will then want to use air-conditioners) and let out as little heat in winter (because you will want to use heaters).  The directional of the window is also part of the calculation.  So basically, if you want big windows you may need to plan for some or all of the following to reduce your electricity draw :  Low E-glazing (film applied to the glass), double or even triple glazing to improve thermal performance, awnings, shuttering and wooden frames rather than aluminium.

Don’t be naive (like me) and believe that the ancient huge trees shading your property will get factored into the calculations.  I was feeling most upset that on one set of ‘referrals’ from council we were advised to install awnings on our very shaded outbuildings. I must confess to feeling rather foolish on taking pictures to council of the trees, cool and moist paving (close ups of moss included!) to have it pointed out that the next owner may just come and cut down the trees and therefore vegetation cannot feature in the calculations around fenestration. Makes sense from that perspective.

You would be very wise to also check that your intended fenestration supplier has had their product appropriately tested:   www.aaamsa.co.za  or www.saggga.co.za or www.safiera.co.za

Renewable Energy

Providing your own energy will not automatically allow you bigger windows.

Fascinatingly, many of the new standards have come into being because of our energy crises, but if your building plans show that you are making provision to make your own via wind turbines or photo voltaic systems (our plan) you will not automatically get Brownie Points that enable you to have for example bigger windows.  The evaluators at council do not have a formula that calculates a relaxation for you because you are generating your own energy.  You might get quite a shock to learn that you need to put in double glazing (double the price) and even lose some of the windows planned. In other words you have not met the category   Deemed-to-satisfy: This path to compliance is met by showing that various building features meet minimum requirements. These include glazing dimensions, insulation thickness and wall types.

To get special dispensation you will have to make a special case. Known as  Rational assessment: This path to compliance allows the use of additional calculations to show that a building, irrespective of glazing size and insulation thickness, uses less energy than either a value provided by the XA standard, or a reference building that complies with the deemed-to-satisfy requirements.  Phew!

Ok, so that jargon just means that if you live in Durban you need to get hold of an electrical engineer who will draw up a whole lot data showing your energy consumption, how much you will supply from your renewable sources and how much you may still need to draw from ESKOM.  Please note, that it must be an electrical engineer, not your architect or your PVC supplier or your favourite blogger’s calculations.  All of this will need to be notarised.    Apparently, however, in the rest of the country this may not be the case as the code only requires only that this “competent person” be qualified on the basis of their experience and training.  It is clear the implementation is not being applied consistently across the country!

Water Heating

Old fashioned electrical geysers are no longer an option. You will be required to install a greener alternative.  You will find some useful information on my posts of December and January on solar and induction geysers and heat pumps.

Water Use, Re-use and Disposal

Our storm water systems are under pressure. All new builds will be scrutinized for their water management plan

Because our storm water systems are under increasing pressure, water disposal on your property will be carefully scrutinized   Your roof area and all your hard surfaces will be measured and depending on the type soil in your area (soil type permitting) you will in all likelihood be required to install an engineer designed soak pit.  These can be very costly in addition to being detrimental to any plants you may have in the garden!

You might be skimming quickly over the paragraph above because you are patting yourself on the back for already making provision for massive volumes of rain water harvesting and storage.  This you are going to use in the loos and showers and washing machine.  In addition, you’ve planned to re-cycle your grey water to irrigate your organic veggies.   You’ve consulted a water expert fundi like Alex Holmes http://www.pulawater.co.za   who has drawn up charts and graphs to show rainfall and your water consumption and you know your excess is tiny.  Your green halo is shining. So you’re exempt right?  WRONG!!  The evaluators do not have rainwater harvesting in their formula so you will need to make a special case for yourself if you want reduce the size of your soak pit.  But do persevere.  Talk to the Storm Water custodians at your local council (not the plan evaluators), make a case and back it up with hard figures and fingers crossed.  There are many sustainable options that could be implemented.

Water management is such an important topic that is going to need its own post to do it justice so watch this space.

Building materials

Bricks/block, roofing, insulation, pipe lagging (yes apparently we need insulation for pipes in a city that never gets cold) etc. etc. must be carefully considered. Many of the materials you use will have associated energy related numbers that may or may not be acceptable.  There is a plethora of new products on the market.  Please be very wary of ‘Green Washing’.  Look for SA Bureau of Standards approval and other relevant ratings and or registrations.

I know that if you put together a competent team on your build and do your homework, you should be able to navigate these regulations with relative ease.

Advertisements