Selfbuilder & Homemaker – July – August 2019

T

here is growing recognition – now

almost universal – that unless

significant action is taken to reduce

the harm we are doing to our world, our

children will have serious problems to

face as temperatures rise and pollution

increases. The most recent report by the

Committee for Climate Change (CCC) is

quite blunt – if we don’t change our

current wasteful ways, the prospects

beyond 2050 are pretty catastrophic!

A significant proportion of self-builders

have decided to make changes for the

better, perhaps inadvertently, because

they know they can build a better, more

attractive home than is generally offered

in the market. Investing in higher

performance standards reduces running

and maintenance costs and raises comfort

standards within the home. Better

insulated homes require less heating and

it is no surprise to find that the majority of

Passivhaus projects are designed by and

for self-builders, as they seek to eliminate

heating (or cooling) costs which continue

to rise.

The ‘fabric first’ approach to energy

efficiency is now recognised as the most

practical means of reducing heating/

cooling demand in buildings. A ‘passive’

building fabric has no running,

maintenance or replacement costs to

consider when it comes to future bills. It

eliminates heating/cooling equipment

and creates a stable, comfortable

environment in the home.

This is where insulating concrete

formwork (ICF) comes into its own.

Systems use lightweight moulded hollow

blocks of expanded polystyrene

interlocked to form a wall. The hollow

core is then filled with concrete which

quickly cures to create a very strong

structure. What was the formwork to

contain the concrete now becomes a

complete envelope of insulation for the

building, with the insulation on the face of

the wall where it is most effective. The

thickness of the insulation varies to suit

energy performance and the concrete

may be reinforced to cater for more

demanding structures, basements etc.

One of the easiest and most readily

available solutions for responding to

climate change is to increase the level of

thermal insulation in buildings to passive

• or even Passivhaus – levels. ICF
  construction can provide these high
  levels of insulation without the need to
  add extra layers of material which add
  time and cost to the project. The
  Wallform ICF system is approved as a
  Passivhaus building system, meaning
  that the design and integration of the
  formwork components do not require
  additional materials to perform to the
  Passivhaus standard.
  Providing a strong, highly insulated
  structure makes it easier to develop the
  building interior using timber or solid
  floors and partitions, with services
  recessed into the insulation prior to the
  direct application of plaster or dry linings.
  The loadbearing strength of the concrete
  also allows for more open plan design
  and flexibility to adapt internal layouts to
  suit changing lifestyles. Plastic plugs are
  used for general wall fixings and the
  concrete core is always available to cope
  with heavyweight items.
  ICF construction is appealing to self-
  builders because the concept is simple,
  with only a limited number of
  components required to build it using a
  handsaw, without the need for specialist
  equipment. The building process is quick,
  and if there is a mistake it is easy to rectify


• as long as the concrete hasn’t arrived!
  ICF suppliers provide training to first time
  users whether self-build or trade, and
  there is a national network of experienced
  ICF builders which is growing to meet
  rising demand.
  There is also a broad choice of ICF

systems available, many of them

imported from Europe or North America,

but several are manufactured in the UK.

At the base level the components may be

delivered flatpack, as ties, panels and

accessories, that are slower and more

complicated to assemble and erect.

At the other end of the spectrum a

limited number of three or four

components are all that are required

to interlock, without adhesives, into the

Providing a

strong, highly

insulated

structure makes

it easier to

develop the

building interior

using timber or

solid oors and

partitions

Robin Miller of Beco Wallform gives his views on why

insulating concrete formwork (ICF) is the ideal

practical choice for self-builders concerned about

sustainability and climate change

ICF – sense and

sustainability

INSULATION

july/august 2019 http://www.sbhonline.co.uk 89