Roof Form Decision Preparation Checklist

Stand where people actually see the house from, such as the pavement, the approach and the far end of the garden, and photograph the existing roofline from each position.

Designers work from elevations that nobody ever stands square to, so your own viewpoints are the honest test of how a change will be seen.

Note which parts of the roof are genuinely visible from public view and which are effectively hidden, since those two situations often deserve different decisions.

Effort spent on a slope nobody sees is effort not spent on the one that defines the house, and owners rarely separate the two deliberately.

Write down what the neighbouring roofs do along the same street or terrace, describing shape and direction rather than materials or colours.

Roof form is the strongest pattern in most streets, and describing it in shape terms keeps the conversation useful when materials are discussed later.

Record whether the existing roof is the dominant feature of the house or a quiet background element, then note which of the two you would prefer afterwards.

This single preference resolves a surprising number of later arguments about eaves, overhangs and how much of the covering is on show.

Photograph the house in flat overcast light and again in low sun, since a roof form reads completely differently when the slopes are catching shadow.

Modelling and texture disappear in flat light, which is why a shape that looks strong in one photograph can look heavy in another.

Decide and record whether the intention is for the new roof to continue the existing one, sit clearly apart from it, or do something quieter in between.

Stating this in one sentence gives a designer more direction than pages of images, because it settles the question every detail then answers.

Note whether the existing roof covering still appears to be available in a similar form, and ask what happens visually if a close equivalent cannot be obtained.

Weathered surfaces rarely match new ones anyway, so knowing early that a difference is unavoidable changes how the junction gets designed.

Write down how you feel about a visible join between old and new roof surfaces, since some junctions between different ages of covering cannot be disguised.

Owners who declare a tolerance for a visible join get a better detail than owners who quietly hope the problem will not arise.

Ask a qualified designer how the proposed form relates to the existing eaves and ridge lines, and record what they say about how the two meet.

Most roof designs succeed or fail at those two lines, and hearing the reasoning helps you judge later drawings rather than just reacting to them.

Confirm locally what applies to roof form, materials and external appearance before assuming any preference can actually be delivered on this property.

Requirements on roof form and materials vary and can differ street by street; confirm with the local planning authority rather than relying on what a neighbour did.

Walk the space below the proposed roof and note where you would genuinely stand, sit or pass through, since usable height is lost at the perimeter first.

Plans show floor area, not the height above it, so the edges of a room under a slope look far more usable on paper than they feel in practice.

Write down which activities need full standing height and which sit comfortably under a slope, such as a desk, a bed head, a wardrobe or low storage.

Matching activities to available height early is what makes a sloping ceiling feel deliberate rather than like a compromise you were handed.

Note anywhere a low roof edge would arrive at the head of a window, since a sloping ceiling meeting glazing is a common and unwelcome late discovery.

This junction is easy to miss on plan and obvious in the finished room, and resolving it usually means moving one thing or the other.

Ask how the chosen roof form affects any structure crossing the space, and whether beams or ties would be visible in the finished rooms.

What structure a roof form requires is determined by a qualified engineer; ask what to expect rather than assuming a clear span is achievable.

Record whether you want the ceiling to follow the roof slope or be flat across, and note where you would accept the transition between the two.

This choice changes the character of the room more than almost any finish decision, and it has to be made before the structure is designed.

Consider whether any void left above a flat ceiling would still be reachable, worth having and served by a sensible hatch position.

Voids created by default are frequently unreachable, which turns useful volume into a space nobody can reach or use.

Mark on a sketch where daylight is genuinely wanted and at what time of day, before deciding how many openings the roof plane should carry.

Openings placed for elevation symmetry rather than for use are how rooms end up bright at the wrong end and dim where you actually work.

Note which opening positions would look towards a neighbour's window or garden, and write down honestly how you feel about that in both directions.

Whether an opening raises an overlooking concern is judged by the local planning authority; confirm what applies before assuming a position is acceptable.

Ask how an opening in the roof plane affects the structure around it, and who decides whether a proposed size and position can be accommodated.

Framing around a roof opening is structural design work for a qualified engineer, not something to settle from a catalogue image.

Write down which openings you would want to reach for cleaning or opening by hand, and which would sit permanently out of comfortable reach.

An opening that cannot be reached is effectively fixed shut and dirty, which is rarely what the owner imagined when it was drawn.

Consider glare and summer heat as well as daylight, and note which rooms in the existing house already become uncomfortable on hot afternoons.

Your own experience of the existing house is the most reliable evidence available about how the new rooms will behave in summer.

Note where the existing downpipes stand, where each discharges, and whether any of them already overflow or splash noticeably during heavy rain.

An arrangement that is already at its limit is important information, and only somebody living there has watched it in a real downpour.

Ask where water from the new roof surface is intended to go, and whether the existing drainage is expected to take it or something new is proposed.

Whether existing drainage can accept additional roof water is for a qualified designer and the drainage authority to determine; confirm locally rather than assuming.

Write down where a gutter or eaves would run relative to a boundary, and whether reaching it for cleaning would require standing on somebody else's land.

Access for maintenance is decided by geometry set at design stage, and there is no practical remedy once the roof is built.

Note where water or sliding snow would leave the new roof, particularly above a door, a path, a parking space or a neighbour's ground.

Shedding points are obvious on a section drawing and invisible on a plan, which is why they are so often noticed for the first time in winter.

Record which parts of the existing wall show staining, moss or green growth, since these usually mark where water already runs somewhere it should not.

These marks are a free diagnostic of the current arrangement and worth photographing before scaffolding and cleaning erase the evidence.

Write down the appearance you want in ordinary words, such as flat, textured, matt, uniform or varied, rather than trying to name a particular product.

Describing the effect rather than the product lets a designer propose options you had not heard of, and keeps the conversation open longer.

Ask what the proposed covering means for the structure carrying it, and who confirms that the weight has been allowed for in the design.

Whether a structure can carry a particular covering is a question for a qualified engineer, never something to settle by looking at what a neighbour has.

Note whether anything is expected to sit on the roof, such as panels, an aerial, a flue or equipment, and raise it now rather than after the design is fixed.

Adding a load or a penetration later means revisiting both the structure and the waterproofing, which is far harder than allowing for it at the outset.

Ask how the covering changes in appearance after several seasons of weather, and keep that answer with your notes rather than relying on a showroom sample.

Almost every roof surface looks different once weathered, and owners are far happier when they were told to expect it.

Consider how the covering meets walls, verges and any parapet, since edges are where a roof either looks resolved or looks unfinished.

Edge details are the part of a roof seen at close range from the ground, so they carry more visual weight than the main surface does.

Note where the roof would come closest to a boundary and whether the eaves, gutter or overhang would project beyond the line of the wall below.

Owners tend to think about walls and boundaries, then discover that the part of the roof projecting past the wall is what causes the discussion.

Ask a qualified professional what applies where a roof edge approaches or crosses a boundary line, and write down exactly what they tell you.

Rights and obligations at a boundary vary by location and title; confirm them with a qualified professional rather than acting on general description.

Write down which neighbouring windows face towards the proposed roof, based only on what is visible from your own property.

Knowing which windows look this way helps you anticipate the conversation, and observing from your own side keeps the exercise uncontentious.

Record whether the new roof would cast shade onto a neighbouring garden or across your own at the hours you actually use the outside space.

Shading is judged in real life at particular times of day, and your own observation of where the sun falls now is the useful starting point.

Note any shared gutter, valley, parapet or roof junction with a neighbouring building, since such arrangements involve somebody else in every decision.

Shared roof junctions usually carry obligations towards the adjoining owner; take advice from a qualified professional before planning any change to them.

Write down how somebody would reach the roof for cleaning or repair, and whether a ladder could stand safely at the points where it would be needed.

Access is a geometry problem fixed at design stage, and a roof that is awkward to reach tends simply not to get looked at.

Note whether gutters would be reachable from your own land along the whole run, or whether some lengths could only be reached from next door.

A gutter that needs a neighbour's cooperation to clear is a recurring negotiation for as long as you own the house.

Ask what routine attention the proposed form and covering typically need, and note who you would expect to call when it is due.

Different roof forms carry very different upkeep, and asking before choosing avoids inheriting a commitment you did not know about.

Consider where leaves, moss and debris would collect on the proposed shape, particularly in valleys, behind parapets and at any low point.

Debris traps are predictable from the shape alone, and identifying them early sometimes changes the design in a small and useful way.

Record what would happen if a leak developed, including whether the proposed build-up would let somebody trace the source without opening large areas.

Never go onto a roof to look at anything yourself; roof access is work for people properly equipped and competent to carry it out.