Spon's Practical Guide to Alterations & Extensions

Andrew R. Williams

• Publisher: Routledge
• Year: 2008
• Print ISBN: 9781138148291
• eBook ISBN: 9781134078714
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

The procedures, the problems and pitfalls of extending or altering property are discussed in this fully updated new edition. The author gives helpful advice on how to make the project go smoothly from beginning to end. This is a practical guide for those at the beginning of their career in building, or who want to be updated on the new regulations now in force.

This new edition incorporates the 2005 Amendments to Approved Document L1B on the conservation of fuel and power. Developments in Computer Aided Design and structural calculations are also discussed. It is invaluable to all those who are trying to act efficiently, correctly and cost-effectively.

PART ONE
Introduction

1 A general guide to drawing the plan

GENERALLY

Figure 1.1 indicates the basic information that will be needed on most plans. The plan is not meant as a solution to all situations but to provide good grounding. If you produce a drawing something like this you are well on the way to getting approval to your scheme. For a typical house extension plan, the following minimum details will probably be required by Planning and/or Building Control Departments (full details concerning Planning and Building Control are provided later):

• (a) Plan of the existing (for a ground floor extension, a plan of the ground floor will probably suffice) – minimum scale 1: 100 (1: 50 is preferred) with drainage details.
• (b) Plan of proposed (for a ground floor extension, showing existing house and extension) – minimum scale 1: 100 (1: 50 is preferred) with drainage details.
• (c) Section through building—minimum scale 1: 100 (1: 50 is preferred).
• (d) Existing rear, side and/or front elevation (as applicable) – minimum scale 1: 100 (1: 50 is preferred).
• (e) Proposed rear, side and/or front elevation (as applicable) – minimum scale 1: 100 (1: 50 is preferred).
• (f) Site location plan. (Note: Most local authorities now require an ordnance survey (OS) sheet.)
• (g) Block plan (sometimes the site location plan will suffice).
• (h) Full specification of materials to be used, cross-referenced to the drawing.

The plans should also show the following:

• (a) The position of the ground levels.
• (b) The position of the damp-proof courses (DPC) and any other barriers to moisture.
• (c) The position, form and dimensions of the foundations, walls, windows, floors, roofs and chimneys.

Fig. 1.1 Plans of proposed rear extension.

• (d) The intended use of every room in the building(s).
• (e) The provision made in the structure for protection against fire and for insulation against the transmission of heat and sound.
• (f) The provision to be made for the drainage of the building or extension.
• (g) The existing features of the site including any trees, outbuildings, those parts which will be demolished and be in sufficient detail to give a clear picture of any new building. Where existing and new works are shown on the same drawing, new work should be distinctively marked using hatching. The materials to be used in the external finish of walls and roofs and their colour should be indicated on the drawings (this is part of the specification on the drawing). On small works, the term ‘to match’ existing is normally sufficient when dealing with roofing and brickwork.

THE BLOCK PLAN/LOCATION PLAN

The location plan can be drawn on the main plan at a scale of 1: 1250. As indicated above, alternatively an ordnance survey sheet can be submitted. The location plan should also show

• (a) The size and position of the building(s) and its (their) relationship to adjoining buildings.
• (b) The width and position of every street adjoining the premises.
• (c) The boundaries of the premises and the size and position of every other building and of every garden, yard and other open space within such boundaries.
• (d) When submitting an application for planning permission the boundaries of the application site should be edged in red.

SCALES GENERALLY

As indicated above, elevations and floor plans are normally to a scale of not less than 1: 100. It is recommended that scales of 1: 50 be used wherever possible as this makes the plans clearer, particularly when drawing sections.

LARGER PROJECTS

Obviously, the more ambitious the proposals, the larger number of plans, elevations and sections that will be required on each full drawing. If the extension or alterations affect two floors, then plans for both floors must be provided (proposed and existing). In theory, the plans should show every floor and roof of the building and a section of every storey of the building. In practice, for smaller projects, it is normally acceptable merely to show details of the floors being altered.

CHECKLIST OF ITEMS OFTEN MISSED OFF PLANS

In Appendix A, I have included a short checklist of items that are often missed off plans or sometimes not addressed at all by the draughtsperson/ CAD operative when preparing plans. The list is not intended to cover every eventuality and could doubtless be extended.

STANDARD SPECIFICATION

In Appendix B, I have included a typical specification. It is very comprehensive and some might say it has an element of ‘over-kill’ about it. Because some items may not be applicable, it is usual to delete the inappropriate items when preparing a specific plan. As it would be extremely tedious to have to handprint this document onto every drawing, the simplest way of reproducing the standard specification on the drawings is by

• (a) Turning it into a booklet form and cross-referencing the main plan.
• (b) Creating a master specification plan.

• (i) You can make the master specification a full drawing in its own right, and copy it and send it in with the project drawing.
• (ii) You can include the specification on the main drawing.

THINKING IT THROUGH

Generally

Although it may seem fairly obvious, whether you are the builder/ homeowner or the surveyor who has been called in to prepare plans, it is essential from the very outset to decide exactly what is wanted. Before visiting a client, I often suggest that they make rough sketches of what they want to do to their property so that it is possible to swiftly discuss the practicality of a proposal once I arrive. It has to be borne in mind that even though most homes lend themselves to extension, you need to weigh up many factors before finalizing the design. I have listed a few for consideration.

• (1) Does the improvement justify the expenditure?
• It is possible to enlarge a property so much that the money invested is unlikely to ever be recovered if and when it is finally sold (e.g. someone enlarging a three-bedroom house into a six-bedroom house in an area that is principally composed of smaller properties is likely to be in this position). I have actually been faced with situations where I have advised potential clients to move rather than extend, for exactly the reasons given above. Admittedly, I have had to forgo the odd commission, but I believe that honesty pays. I certainly would not wish to slip to the level of a high-pressure salesperson and advise people to carry out a project that I believed to be foolhardy.
• (2) As well as the pluses are there minuses to the proposals?
• Take as an example the family that want a dining room built onto their house. An extension of this nature that could only be reached via the existing kitchen is not as desirable as a dining room off a hallway. Kitchens can be untidy and smelly places whilst cooking is going on. Having to take guests through a working kitchen in order to reach the dining room might, in the long term, become an embarrassment. What if you wanted to impress your new boss or a highly critical relative? Having to drag them past pots and pans is far from ideal.
• (3) What will the effect be on the external appearance of the house?
• If you drive around your home town for a short while, you will come across many examples of badly thought-out schemes. How about these for starters:
  • (a) The two-storey side extension to a normal two-storey house. The original house has a tiled roof but the extension has a flat roof. Admittedly, most Planning Departments nowadays reject applications like these, but some have been built. Very few people would describe this type of extension as beautiful, but it is amazing how many were built this way just to save money. (My office has recently designed a series of new tiled roofs to replace leaking flat roofs in our area when the owners suddenly realized that the original flat roof had been a false economy.) No doubt one or two planners let out a cheer as they were replaced.
  • (b) The loft conversion that is so dominant that it completely destroys the existing roof line.
  • (c) The extension built of badly matched bricks. (It saved money but the owner now lives to regret the penny pinching.)
• (4) What will be the effect on adjoining properties?
• I have known several situations where good neighbours fell out merely because one ignored the wishes of another.
• (5) Is the proposed extension oversized and badly sited?
• Badly designed extensions can result in loss of sunlight/outlook both for the instigator of the extension and the adjoining owners.
• As people do still ignore obvious design considerations, some sort of control is needed, and that is the subject of the next chapter.

2 The need for control

WHO CARES WHAT THE NEIGHBOURS THINK?

Do you remember the newspaper articles and TV reports about the man who decided that a house was not really a home unless it had a very large model fish on the roof and a secondhand armoured fighting vehicle in the front garden? I gather from the media reports that his neighbours are not exactly pleased with his ‘follies’.

COMMON SENSE IS NOT ALL THAT COMMON

There is an old saying that common sense is not all that common. Do you remember the newspaper story about the man who decided that it might be nice to have a basement under his house? You know the one, he laboured away all summer and as he was digging, he came across some obstructions in the ground (in the trade, we call them foundations), so he dug them up and the house, naturally enough, collapsed.

Knowing newspapers it might have been an apocryphal story, but I have seen members of the public doing some extremely stupid things over the years, either because they did not know any better or because they had decided that the rules did not apply to them. Then there is the person who is doing something as a ‘matter of principle’. Solicitors love them because as they say ‘principles cost money’.

Unfortunately, there will always be some members of the ‘it’s-my-property-I’ll-do-what-I-want-with-it’ brigade in every area, and that is why the various rules and regulations become more strict as the years go by.

At this point, I am going to toss in a personal anecdote as a further illustration. Many years ago I was asked to prepare a set of plans for an extension on a property. As the enquiry was generated by a tradesman builder that I knew reasonably well, we set off together to visit the house in question. Once under way, Tony, the builder, explained that he had given the owner a budget quotation for the work based on a cost per square foot of floor area, and wanted to come with me to ensure that he had a good look around before firming up his price.

Once we arrived and had been invited in, Tony gave me a puzzled look and then whispered ‘Funny house this!’, and then went back to staring at the patch of new plaster on the ceiling. While Tony had been eyeing up the plaster, I had been weighing up a timber post in the middle of the living room. Then I realized that there was a sink on the far side of the living room. It was at that point that Tony drew my attention to the fresh plaster patch. This had, without any doubt, been the result of repair works following the removal of the chimney breast in the living room.

Being concerned about the structural integrity of the property, I said, ‘Have you put in RSJs (rolled steel joists) to support the remaining chimney breast upstairs?’ The owner looked at me and shook his head. It was at that point that I glanced around the rest of the house with more enlightenment. Only moments later, the truth dawned! This silly man had demolished all the load-bearing partition walls downstairs; the entire weight of the first floor was supported on the 4 in × 4 in (100 mm × 100 mm) wooden pole and the external walls. It was then that I warned the owner that I considered the whole property structurally unsound. I think that I upset him because the gentleman in question made it clear that if it had not been for his wife’s insistence he would have built the new extension himself as well.

As far as he was concerned, he could see no reason for submitting plans to the council. It was all just ‘red tape’ designed to keep overpaid civil servants in the lap of luxury. He could not see anything wrong in his previous ‘do-it-yourself’ attempts. It was at that point that Tony and myself both came to the same conclusion: we did not want anything to do with this character.

However, what if you were the next door neighbour? Bearing in mind that this house was a mid-terraced property, would you like to live next door? When the house collapses, as it will in the fullness of time, and damages other houses, what will happen? Maybe someone might even be killed!

It is people like the man above, who do not know what they are doing, or who skimp to save money, that make controls so essential. Such examples also prove the need for competent designers and builders. People who have no knowledge of building construction and are not prepared to learn should not dabble.

3 Planning and building control

INTRODUCTION

As I have indicated in the previous chapter, some control is needed over ‘development’ and most sensible and informed people appreciate this, even though at times they become frustrated by the fact that the procedures seem to take so long.

It should also be obvious that because of the actions of a few unthinking people in the past, there is now very little that can be done to a property without having to consult the local authority (the local council). Thinking people would probably also agree that if the regulations were relaxed that the ‘fringe element’ would return to their old ways. To some, having to conform to rules is seen as an infringement of their civil liberties, but as I have tried to indicate in the previous chapter, control over ‘development’ is no bad thing.

Although there are exceptions (which will be discussed later in more detail), no work should commence unless the necessary approvals have been obtained from the

• (a) Building Control Department (or an Approved Inspector)
• (b) Planning Department/Planning Authority. (Note: As explained in later chapters, some alterations and extensions are Permitted Development and do not require planning approval.)

In some areas, such as conservation areas, additional approvals are also required. (Practically speaking, ignoring the time limits that both departments are supposed to work to, in my ‘patch’, it normally takes at least two months to go through all the procedures, but it can take longer.)

In the main, the Planning and Building Control Departments come under the control of the local authority. However, sometimes the planning function will be either partially or totally under the control of a non-elected body such as a New Town Development Agency. With privatization now being the new buzzword, councils have also lost some of their authority over ...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Preface to Second Edition
• Preface to First Edition
• Acknowledgements
• Part One: Introduction
• Part Two: Householder Developments
• Part Three: More on Building Control
• Part Four: Building Construction
• Part Five: Mainly for Consultants/Conclusion
• Appendices