Campaigning for real windows

LONG-TERM COSTS

Research done by the Northern Consor-

tium of Housing Authorities (NCHA) in

1988 into the refurbishment of existing

housing with a 30 year mortgage period

shows softwood the cheapest option, with

upvc and hardwood more expensive.

The Department of Energy pamphlet,

Insulating Your Home contains the follow-

ing Paragraph:

Modern aluminium frames are virtually

maintenance free. Their hardwood sub-

frames will need occasional oiling or

varnishing but this won’t take the time

or, trouble needed to maintain tradi-

tional wooden frames

The claim that the product is

maintenance-free is misleading, for exam-

ple the life-spans of gaskets, sealed double

glaze units, sealants and some ironmon-

gery are all shorter than that of the frame.’

The neoprene gasket which is fitted

between the glass and the frame/bead has

an estimated life-span of between five and

ten years.5 The London Borough of Hack-

ney recently replaced 262 upvc windows

with hardwood at a cost of £92,000

because of their inability to obtain the cor-

rect replacement components.”

Method

installation

cost (E)

Double glazing 120-200(DIY)

2,500-6,000

Plastic secondary glazing Professional sealed unit

Professional sealed unit

Table 2, Long term costs (data from Steel

Window type

initial

Building

Fixing in

cost of

prepared

window

opening

BS 644 timber

painted

Hardwood timber

stained

BS 6510 steel

galvanised

BS 6510 steel

powder coated

BS 4573 aluminium

anodised

105

BS 4573 aluminium

acrylic

BS 4573 aluminium

powder coated 95

upvc 110

Self-finish aluminium and upvc frames

require regular cleaning, to maintain

appearance and painting may be necessary

after, 20 years.7

The NCHA suggests that, should the

future reveal that there was, one inherent

flaw in the concept of upvc windows

(something which many architects fear),

the major failures may not be due to the

frames but to the ironmongery.

The normal product certification by the

British Board of Agrément refers to a win-

dow life of 20-25 years. What cannot be

predicted are the availability of compo-

nents, the costs of maintenance or advances

in technology in future years.

GUARANTEES

Sealed double glazing units are, at best,

guaranteed for five or ten years against the

failure of the seal.

Guarantees for components offered by

manufacturers are not legally binding, so

purchasers are relying on their goodwill to

fix anything that goes wrong. The only

guarantee which is legally binding is that

offered by the person with whom they have

a contract — the installer. Unless the guar-

antee is insurance-backed, problems could

arise if the company goes bankrupt or is

taken over. The new owners are under no

obligation to take on guarantees offered by

the first company.’

This case study is one example of what

happens when a resident wishes to replace

the windows in a house, and illustrates

some of the high pressure sales techniques

used. In the author’s opinion, people not in

possession of the relevant information

would be seriously misled by many of the

claims.

Whilst it is difficult to compare a plas-

tic or aluminium sliding sash-cum-tilt-

and-turn window with a traditional

timber sash window, on a cost basis it

would seem that the plastic and alumini-

um replacement windows cost much the

same as purpose-made timber ones. For the

casement window, for manufacturing rea-

sons, timber windows cost far less than

upvc and aluminium.

Off-the-peg joinery was the cheapest of

all but additional charges would have been

incurred if the fabric of the house, or the

window, had needed altering.

Neither plastic nor aluminium windows

have profiles capable of matching tradi-

tional windows, unless it is a very simple

casement. At the bottom end of the mar-

ket, on a DIY basis, standard products

would be relatively cheap provided that

the correct size of window could be found,

but details of glazing bar profiles and pane

sizes are unlikely to match.

Modern windows would undoubtedly

eliminate draughts and maintenance in the

short term, and provide thermal and noise

insulation, but this sort of comfort could

be achieved much less expensively by

using secondary glazing, either fitted pro-

fessionally or DIY.

In terms of annual heat savings and cost

recovery times, installing upvc and alu-

minium double-glazed windows is almost

the least effective measure and costs are not

likely to be recovered within the house-

holder’s tenure or even lifetime.

Guarantees of up to ten years are given

but their value is questionable. No one

knows exactly how long plastic windows

will last. With the plastic window tech-

nology still in its infancy, using a good

quality traditional material, which offends

no one, and a well established joinery firm

which understands the necessity of correct

detailing, building and maintenance tech-

niques, would appear to be the wisest

146

course of action.

154

REFERENCES

1 Parissien, S: “Framing Opinions” conference.

143

2 Fidler, J: “Framing Opinions” conference,

3 Dept of Energy: Insulating your Home.

132

4 Northern Consortium of Housing Authorities

study, p3.

5 NCHA study, p24.

162

6 Fidler J,: Architects’ Journal October 1990.

7 NCHA study, p45,

160

8 “Which” magazine, Sept 1990, p500,

170

Anne Ho/den was until recently at Aug/ia Polytechnic. This

article is abridged from a dissertation for her Environmental

—

Planning degree

Tablel. Installation costs, savings and cost recovery times’

Loft insulation

Hot water

insulation

Annual

Cost

savings (£

Recovery

100-150(DIY)

150-250 (contractor)

6-8 (jacket)

12-15

(pipes)

Cavity wall insulation 320-450

50-60

15-30

5-10

Solid wall insulation

thermal board

2-3years

3-5

years

0-1

year

1-2

years

1 50-250(DIY)

1,300-1 ,500(contractor)

60-80

4-6 years

60-80

15-30

15-40

Window Association).

2-3

years

20 years

4-7

years

+50 years

Cleaning Total

ev cry

six

months

Decoration

initial

cost and

Maintenance

CONTEXT 33