The Birch Corporation Case Study
The Birch Corporation was established over thirty years ago by Mr George Birch who started his life in the building industry as a plasterer. More recently the company has moved its headquarters to Milton Keynes and undergone a management buyout.
With its roots firmly in the Bedfordshire, Buckinghamshire and Hertfordshire areas the company has a reputation for providing quality, value for money homes for its customers.
One of its most recent developments has been Ashton Gate in Flitwick. The project comprises of twenty-two dwellings including; detached, semi-detached and terraced homes as well as three story town houses.
The homes have sold well despite the Birch Corporation’s biggest challenge - the elevated railway which runs at the back of the properties.
As well as the standard UPVC 24mm double glazed units, the architect specified that any windows in habitable rooms backing on to the railway line must have additional secondary glazing. This was in order to meet World Health Organisation’s noise recommendations, which state that the maximum decibel exposure levels for residential properties should be from 30-35dBA in the bedroom and 30-40dBA in the living room.
Another noise reduction feature incorporated into the properties is that they are designed with no opening windows at the back of the properties.
Bruce Palfreman, Construction Director at Birch Corporation explains “Although double glazing is in standard use in housing these days and has considerable benefits over single glazed units, it does not demonstrate the significant noise reduction properties that we were looking for in this instance. I had visited the Storm Windows stand at an industry exhibition a few months earlier and was interested in the technology they used to produce their secondary glazing. Unlike most secondary glazed units it uses no wooden sub-frames and each window is individually surveyed for a perfect fit.”
Due to the unique ‘thermo-magnetic’ sealing system incorporated by Storm Windows, extremely good air tightness is achieved. This is important for maintaining high levels of sound insulation. Air gaps of only 1% of the total window area can increase the sound transmission by up to 10dBA. Therefore, it is important that secondary windows should be purpose built to each individual window. Because of the slim-line nature of Storm’s secondary glazing it was also possible to reduce the 175mm gap between the double and secondary glazing and still reduce the decibel level in the rooms by between 4 and 6 decibels.
Martin Walford, Technical Director at Storm Windows adds “People usually associate Storm with historic or specialist windows that require bespoke treatment due to intricate or unusual designs. However, our range of products is equally suited to new build or conversion projects.
The installation of twenty-eight, slim-line lift outs, by Storm’s own fitters, went smoothly and they were careful not to interfere or slow down work being undertaken by the team from Birch Corporation around them.
Mr Palfreman continues, “We were surprised that despite the quality and high technical specification of the windows provided by Storm, they were extremely competitive and excellent value for money. We believe our customers have an excellent solution at a very reasonable cost to what could have been a major irritant. We are delighted that a significant number of the homes backing onto the railway line are now occupied and we have received no complaints about the levels of noise.”
Mr Palfreman, The Birch Corporation
“We were surprised that despite the quality and high technical specification of the windows provided by Storm, they were extremely competitive and excellent value for money. We believe our customers have an excellent solution at a very reasonable cost to what could have been a major irritant. We are delighted that a significant number of the homes backing onto the railway line are now occupied and we have received no complaints about the levels of noise.”