Which qualifications does your builder have?

Most of us will have no idea what qualifications builders have. We invite people, for a number of different reasons, into our homes to work on our most expensive assets and yet, we don't know whether they are qualified to do so.

Is this madness??

I am currently doing some work for the Construction Industry Training Board on training for construction professionals at NVQ Level 3. Looking at the qualifications from Level 1 up to 3 it does seem that anyone holding Level 2 should be able to do most things on more recent housing stock. So why do we see so many mistakes with common building work?

Last year I was speaking to Cardiff and Vale College and it seems as though a common occurrence is that people start their Level 1 (this represents a basic understanding of the topic and the main basic key skills), but only a relatively small percentage come back to do their Level 2 (this represents the industry standard - what people need to know to be able to do their jobs properly). Where do they all go? Well it seems that some decide that it is not for them, but many others start work.

So in this country we have the ridiculous situation where anyone can put a Builder logo on the side of a van and start trading as a legitimate business. No need for a qualification, no need to show that you understand how buildings work or that you can undertake the more complicated work with confidence, competence and skill.

In other countries you have to have a qualification to build, but not here. So bear this in mind when looking for a builder. Also the marks associated with FMB and NFB are worth noting. They do require a portfolio of work to be seen in order to join, but no official qualifications. So there is some reassurance here, but again no training.

Whilst there are some issues with the standard training, especially since we don't recognise the differences between modern building materials and practices compared to the historical ones required for lots of refurbishment work, it is the best way of at least having an underlying competence. So look for a minimum of NVQ Level 2 for standard works, a Level 3 for more complex requirements and a Level 3 Heritage Skills qualification for work on pre-1919 buildings. If there are no qualifications to be had, then look for a portfolio of work and references.

Good luck!

Green Deal Measures - What are they installing?

On the news that the Green Deal has installed 1,000 measures I thought that I would have a look at what they are actually doing.

I was pleased to see that the bulk of what is being done is really quite standard and unlikely to cause damage to the housing stock. Most of the work is changing people's boilers to more efficient ones (37%) and also the related improved heating controls (15%) and hot water tank insulation (9%). Then there is the standard stuff like loft and cavity wall insulation (10%). The only real surprise was that people are having photo-voltaic systems installed as well (16%). The high interest rate associated with the green deal would counteract the financial benefit accrued by the Feed in Tariff, so one must assume that people are doing it for all the right reasons (ie to cut carbon emissions and to localise energy production).

Not too many people are doing solid wall insulation (14%), so this is reassuring, especially since most of the activity in this area is being completed on more recent solid walls rather than the pre-1919 types. Working on concrete walls is much less risky than brick and stone walls.

So even though I am not a fan of the Green Deal, due to all the issues of the poor advice generated by the software, the cost of the loans and the inaccurate financial projections given, it does have a use. Where people cannot afford the capital for 'improvements' this is a way of giving people access to the money to make some positive changes. So even if the measures prove not to be cost effective for the recipients (although with the price rises recently announced even the poor calculations given might find a 'Get Out of Jail Free' card) at least there are some apparent carbon reductions for the rest of us.

Lime - that's less than half the problem!

Sustainable and historical bodies talk about the need for lime renders and mortars in pre-1919 solid walled buildings and rightly so. Lime is a porous material and will allow moisture to pass through it. This allows the walls to 'breathe' and so can help to keep them dry.

All well and good. However, when you make up a mix of lime render what is the main constituent? Lime? No, the bulk of the material is the aggregate. I think that this can be a problem, because the main aggregate that we use is the cheapest and most common one. Sand.

Sand is not breathable / porous and so if you use lime and sand for renders then all the moisture can only travel through the lime. Given that rainwater is slightly acidic means that the lime will be weakened more quickly. However, if porous aggregates are used (or at least a portion of the mix is made from porous materials like limestone, brick dust etc) then the aggregates will take a lot of this load off of the lime, thus making it last longer. Also if external finishes are meant to be 4 times more breathable than the main structure then having a porous aggregate helps to achieve this. 

Lime with a porous aggregate is also more likely to work in an 'osmotic' manner rather than in a capillary way with sands. This means that it can 'suck' moisture out of walls more easily. So as you can see the term 'Lime render / plaster' needs a little more clarification.

I think that the choice of lime and its associated aggregates needs to be more scientific in its specification, especially since choice might also be driven by a range of other factors including:

Exposure 

Underpinning substrate 

Orientation 

Historical colours of renders

So we need to be careful. The best for renders are a mix of particle sizes and sharp angular edges and so if we allow ourselves to be driven by factors like historical use we need to take care. Many old render mixes were dictated by available local materials and these might not be best suited to the location etc, so planners might insist on a mix that is not particularly appropriate for the building!

There are other issues that surround all of this including:

Sand types (smooth or angular)

Salt contamination

Application methods

However for the sake of brevity, are there any broad recommendations that I can give?  

Well, after much thought I have ended up in the Welsh Lime Works camp where we tend to advise people to use lime putty (based on limestone rather than chalk) with a limestone aggregate, applied with a pump and then finished off with a limewash (again based on limestone). This creates a very breathable mix that allows buildings to work in harmony with nature, but it is worth noting that all projects needs to be individually approached.

Which Cavity Wall Insulation?

Cavity Wall insulation for typical existing homes comes in a number of forms:

1. Beads
2. Beads with adhesive
3. Mineral fibre
4. Foam

I recently looked at a couple of the more popular options in the UK and found to my surprise that there is very little technical information available on them. No technical details on installers or manufacturers websites and when I called one of the biggest installers I was told that there was no-one there who could answer my questions (despite being quite basic) and that I would either have to speak to a surveyor or have an on-site visit. So they are keeping some basic data hidden away. Not sure why as there is nothing really to hide. Also all the sites give out basic info on the process of installing, benefits etc, but there is no mention of any particular issues to bear in mind.

All of cavity wall products are injected and all will do the required insulation job on paper, however there are some major differences between them. I shall also highlight some concerns / factors that you might wish to bear in mind when choosing.

One major factor before you even start is to ascertain whether your property is actually suitable for cavity wall insulation. Many cavity walled properties that were built before WW2 did not have wide cavities and many are also full of builders waste. So make sure that your wall is capable of safely having insulation installed.

Second major factor is: How exposed is the site? Is it prone to wind driven rain? The way that cavities are designed to work is that the outer 'skin' is allowed to get wet and then the cavity keeps the inner wall dry. This means that the walls are actually quite poor at insulating, but that they are at least dry. By filling the cavity with a material, this can allow water to pass from the outer skin into the inner one. Not good! So your outer wall needs to be in good condition with intact render / mortar, not affected by leaking gutters or down pipes etc.

Third major factor is: Are you planning on any replacement doors / windows / extension works etc in the future? Some insulations are loose fill and so if you disturb the wall then they will just fall out. Thinking ahead will allow you to make the right choice in the longer term, otherwise you are just making extra work for you or for future occupiers.

Fourth major factor is: Do you have good seals around anything that goes through the wall? Insulation companies are not good at making good a wall before work. So if you have penetrations through the wall for waste pipes, drains, water connections, gas connections, air bricks etc, or even poorly sealed doors and windows the companies often just fail to inject insulation in these areas. Thermographic images taken on insulated properties often show that cavities are not insulated around 'weak points' like doors, kitchens (where there are lots of services), above window lintels etc. This causes cold spots in these areas and can lead to damp and mould forming.

So back to the choices.

1. Beads - Beads on their own form some of the most insulating choices. The beads that are injected though are loose fill. They can also form a bridge between the two skins. They can rely more on gravity to fill the cavity rather than pressure when installing.
2. Beads with adhesive - These are generally less insulating, but are pressure injected in order to make the glue work. They are regarded as being water proof and so should keep any water away from the inner leaf (assuming that they is installed correctly). The pressurised installation should mean that it is more likely to fill all of the cavity (and blow out of any weak points!)
3. Mineral fibre - These are sold quite often as being fire proof. However, fires in cavities are not very likely and so the toxic fumes from beads are not too much of real hazard. Mineral fibre is also a loose fill, although it does bind together better than beads. It can also form a bridge between the skins if the outer skin fails (just like the beads).
4. Foam - This is not fitted these days as there have been numerous cases where the foam has failed over time and left a right old mess in the cavity. If you did have foam installed years ago then you may wish to revisit the condition of your walls. There are companies who will remove failed foam and re-install a more appropriate insulation. A thermographic image should identify if your walls do have a problem.

Overall then, there is of course a need for cavity wall insulation in many houses, but you need to think about the suitability of the walls, the need for continual maintenance of the outer skin to ensure that it is not compromised and also the choice of the material for the fill. Good luck!

CADW Heritage Cottage U Value data

CADW purchased this old terrace in Cwmdare in order to preserve it for future generations to see how workers cottages were originally built, but also to see what sympathetic improvements can be made in order to bring it up to more modern standards.

This is a balancing act for the team, but they have already done a lot of work to see how the building actually performs compared with our modern expectations. One of the most important elements in today's world is how insulating the fabric of the building is. Walls form a major component of this. If you are a reader of this blog you will not be surprised to find that the walls were actually 30% better than predicted by our modern spreadsheets predicted.

More information on CADW Heritage Cottage and its refurbishment can be found by clicking here:

Ultra Insulating Windows and Doors

Eco Home Centre has a great relationship with ARU Joinery in Estonia. Now the lovely people at ARU have developed a brand new ultra insulating range of doors and windows for the Passive House / Code for Sustainable Homes Level 5 and 6 market.

The Nordic Range is made from solid wood so there is no chance of the frames de-laminating. (De-lamination has been a cause for concern on insulated windows and doors as there is an inherent weak point in the structure.) These frames are chunky at 92mm thick, but this is required to house the 52mm deep triple glazed units. The frames, though, do not look over heavy (despite being very heavy!)

The U values achieved are very impressive. The glazing itself gives a Ug of 0.47 and a standard window gives an overall Uw of 0.78. Compare this to the Building Regulations standard of around Uw of 2 and we start to see how well these windows and doors perform.

The Nordic series of products is wide ranging and includes:

• Inward and outward opening doors and windows;
• Sliding patio doors; and
• Folding patio doors

All are also available in aluminium cladding for extra weather protection for those hard to service areas.

So if you are looking for some great high performance, high specification windows or doors then have a look at http://www.arugrupp.ee/window-and-door-production/products/facades-and-conservatories or give us a call.

Green Electricity Price Freeze and Other Good News

Just had an email through from Ecotricity (whom we use at home, both on our Dual Fuel, but also for the Feed In Tariff for our PV panels), that states:

1. Price Freeze until 2014. So they will be freezing their prices until the New Year
2. 100% Green Electricity tariff is now their only tariff
3. They will cost less than each of the Big Six standard regional tariffs
4. Green Gas will be guaranteed 'Frack Free'

So, with prices increasing for many people, it might be worth investigating a fully green option that may well be cheaper both for you and the planet.

Another option for those in Wales is that DTA (Wales) have negotiated a deal with the big energy boys to reduce costs by a mutual buying arrangement in partnership with The People's Power CIC. So if you are more worried about cheaper prices rather than a green tariff then check out https://www.cheaperenergytogether.org/p/dtaeag/

As winter approaches it is important that we take control over our use of energy and these are two really great ways forward.