Windows and doors provide security, thermal and acoustic insulation and affect the aesthetic appeal of a property. Specialist manufacturer Mumford & Wood tells us what to consider if you are thinking of replacing existing windows and doors or if you are embarking on a new-build project. New windows and doors may be costly, but it’s important to spend as much as your budget will allow to get the best available. If well-maintained, they will last a lifetime.

Q. Do you need planning consent to change windows and external doors?
A. In certain instances, such as in a conservation area, always check with your local planning officer before changing windows and doors. Be prepared to submit your application in writing, with window drawings prepared for you by a specialist. In the case of a listed property, you will definitely require consent to make a change to any window or doors. An inspection may be required. If your upgrade involves the replacement of single glazed windows and doors with double glazed products the success of your application will depend entirely on the opinion of the planning officer and the strategy employed in the specific area. He may be sympathetic with your need to thermally upgrade or to replace rotten, condensation-soaked windows but may object in terms of traditional or period aesthetics. In this case they may suggest that you undertake repair or consider secondary glazing instead of replacement. Mumford & Wood have great experience in working with local planners and can often resolve the problem by adapting a specific design or detail to help achieve a like-for-like replacement suited to the area.

Q. How do you provide energy efficient windows for listed buildings?
A. Double glazed, factory-finished Conservation™ timber windows by Mumford & Wood offer the very highest levels of thermal and acoustic performance, are A+ rated and provide a U-value of 1.3 W/m²K which exceeds the requirements of current Pt L Building Regulations. Made-to-order authentic period replacements in the Conservation™ range are difficult to discern from original windows. However if your local planning officer will not approve a double glazed replacement your only option is to consider secondary glazing, which is not entirely aesthetically pleasing as it may obscure elegant period sight lines. Well designed, energy efficient timber windows and doors will add to your comfort, will reduce energy consumption and associated costs, as well as control CO₂ emissions for the benefit of our families and the planet.

Q. What type of glass do you use in windows?
A. Products in Mumford & Wood’s Conservation™ range use factory-finished, argon-filled double glazed panels with low E coating as standard. This can be changed to obscure glass in modesty areas, or laminated glass in locations requiring additional protection such as on landings and staircases. Mumford & Wood offer a choice of 12, 14, and 24mm double glazed units with 24mm being standard. The wider the space between the two glass panes the higher the thermal performance; more slender 12 and 14mm units are aesthetically ideal in period properties but are less energy efficient. Conservation™ historic single glazed windows with high performance weatherseals to help thermal performance are also available. Mumford & Wood also offer the option to specify ‘antique glass’ with all the natural visual defects and variations of original crown glass.

Q. What is the best type of timber for windows and doors?
A. Achieving high performance windows that will look good for years to come requires the use of premier grade materials; here engineered timber takes centre stage. It provides strength and stability which will improve security, provides greater thermal performance, comfort and acoustics, and remains looking good for longer. The timber required for high quality windows and doors must meet the performance standards laid down by the regulatory authorities in the UK and Europe.
European softwood is grown right across the continent on a line of latitude equal to London and northwards; the further south the lower the quality, the further north, the better. For example, the quality of softwood grown in Scotland and Wales is only suitable for fencing and garden buildings; in the very far north – north of the arctic circle in Russia, Finland and Sweden, the very dense, slow growing wood is the variety most suited for high quality joinery products.
This timber is taken from the heart of the tree where the real strength lies. In a matter of weeks it will start to curve and twist unless treated and kept in perfectly humidified conditions. Resin pockets and knots are cut out. Six metre lengths of lumber are ‘finger jointed’, a process like locking fingers together, and glued to create solid wood which is stable and strong.
Mumford & Wood use Siberian larch, a European softwood, which is very dense, intrinsically anti-fungal and resistant to insect decay. The condition of the timber in terms of moisture content and technical properties such as density and dimensional stability are relevant to the strength and stability of the finished product. Ideally the moisture content of the timber when received into the manufacturing environment should be no less than 12% and not more than 18%.

Q. What are ‘conservation’ window and doors?
A. Products manufactured by Mumford & Wood within the company’s Conservation™ range include box sash windows, casement windows, special shapes, French doorsets, bi-fold, entrance and balcony doors. They are ideal for period refurbishment projects and traditional-style new build properties. They are created with all the design considerations of a period window to achieve authentic like-for-like replacements enhanced with 21stC levels of thermal and acoustic performance, as well as the highest standards of security.

Q.  How do you select the type of external door that best suits your home? And why is it normally necessary to have a front door made-to-order?
A. The original front door of your home was made to order to fit the doorway and it is unlikely that it will be precisely the same size as a standard off-the peg door. If you are thinking of replacing it, always replace an entrance door with a style that suits the architectural period of your home or it could affect the value of your property. Mumford & Wood offer made-to-order doors in every architectural style, with or without glazing, fanlights, fixed glazed side panels. Modern trends include etched street numbers and house names on glazed panels, even in traditional designs.
Using only sustainably sourced, engineered timber with raised and fielded panels, Mumford & Wood’s entrance doors are strong and durable and, if well maintained, have an expected life of 60+ years. Security is paramount and Conservation™ doors are Secured by Design (SBD), the UK police flagship initiative which aims to design-out crime and requires that products must meet challenging test criteria before they can carry SBD certification.

Q. What type of windows and doors can you provide?
A. Mumford & Wood supply made-to-order traditional Conservation™ sliding box sash windows, both single and double glazed, operated by traditional cords and weights or the more modern spring balance method of operation, with or without glazing bars. These can be made to coordinate with Conservation™ casement windows and fixed glazing, special shape windows such as triangles and bullseyes, and bi-folding doors, entrance, balcony and French doorsets. They all meet the highest standards of thermal, acoustic and security performance, carry the BSI Kitemark and are Energy Saving Trust listed.

Q. Do you offer warranties?
A. Mumford & Wood offer market-leading warranties from date of delivery: wood components, frame and sash, are free from defects that could affect performance for a period of 30 years.
Three coats of opaque finish warranted for up to 10 years/stain for 6 years.
Ironmongery and seals, hinges and handles for a period of 10 years.
Double glazed units and glass free from failure for a period of 10 years.
Sash spring balances for a period of 10 years against functional failure.

Q. How do windows and doors affect the value of your home?
A. Good quality timber windows and doors play an important role in the thermal performance of a home, and in the overall aesthetics of the property. The street presentation of the house is the biggest selling feature and nothing adds more to this than well designed, good quality windows and doors.

www.mumfordwood.com, 01621 818155