Addition Foundation Discussion Preparation Checklist

Write down who has been engaged on this project so far and who has not, then note which foundation questions you have been asking of each of them.

Owners often discover they have been asking the person who will build about matters that belong with the person who designs.

Ask your designer early who would be responsible for designing the foundations, at what point they would become involved, and what they would need in order to start.

Left unasked, this topic surfaces only when a scheme is already drawn, which is the point at which it is most disruptive.

Foundation design is carried out by a suitably qualified professional working from their own investigation, not from anything an owner has written down.

Separate the foundation questions you are asking out of curiosity from the ones that must be answered before a scheme can sensibly be drawn.

Both kinds are worth asking, but only one kind should be holding up a decision, and the two get muddled easily.

Note whether anyone has offered you an opinion about the foundations here without having visited, and record it as conversation rather than as information.

Confident opinions travel fast among neighbours and online, and they are difficult to dislodge once someone has repeated them a few times.

An opinion offered without a site visit establishes nothing about your property and should never be relied on for a decision.

Ask what a first visit would actually look at, what it would not cover, and what would still be unknown at the end of it.

Knowing the limits of a first visit prevents you treating an initial impression as a settled conclusion.

Ask who would deal with the local authority on matters relating to the works below ground, and note the answer rather than assuming it falls to you.

Responsibility for dealing with the authority is often assumed by everybody and held by nobody.

Write down roughly when the property was built as far as your paperwork suggests, and label it as taken from documents rather than known for certain.

Age shapes what a professional expects to find, though a date taken from paperwork should be handed over as exactly that and nothing firmer.

Note what the outside walls appear to be built of at low level, describing plainly what you can see and saying so when a render or a paint finish hides it.

Saying you cannot tell is more useful than a confident guess, and it is a perfectly acceptable answer to give.

Record which parts of the building were clearly added later, where the join shows in the brickwork or render, and whether the roofline changes there.

An earlier addition is the most likely place for a change in what is below ground, and the join is usually visible from the garden.

Note anything you have ever been told about the foundations here, where it came from and when, including remarks made by a previous owner or a neighbour.

Second hand information is still worth passing on, provided it is handed over labelled as second hand.

Nothing said informally about foundations establishes what is actually there; a qualified professional would have to investigate.

Write an explicit list headed with the things nobody currently knows, such as depth, construction and condition below ground, and take it to the meeting.

Handing over a list of unknowns is unusual and immediately useful, because it stops assumptions being made on your behalf.

Photograph the base of the wall along the whole elevation the addition would join, both close up and stepped back, and keep the images dated.

A consistent set of photographs of the wall base gives a professional context before they arrive, and it asks nothing of you but a walk round.

Peg, chalk or line out the footprint you have in mind so that any conversation on site is about a real shape rather than a rough gesture towards the garden.

Everybody has a slightly different picture of where the addition goes until somebody puts it on the ground.

List what stands inside the marked area now, including paving, a shed base, an oil tank, a washing line post, a step or an inspection cover.

The contents of the footprint are the first practical constraint on any groundwork discussion, and they are all owner observable.

Note how the marked area sits in relation to the boundary features you can see, describing it as an observation rather than a statement about ownership.

Where the fence stands and where the boundary legally runs are two different things, and only one of them is visible.

Boundary positions are legal matters to confirm through your own title documents and appropriate advice, never from what is on the ground.

Photograph the marked area from an upstairs window if you can, so the shape and its relationship to the house and garden reads clearly in one image.

A view from above communicates the proposal faster than any description, and it is easy to repeat if the shape changes.

Note whether the ground within the marked area is level, sloping or stepped, which way any fall runs and whether there is a change part way across.

A slope across the footprint influences everything discussed below ground, and it can be described in plain terms by anyone standing on it.

Record how the marked area is actually used at present, since that tells everyone what would be disrupted and how much that disruption matters to you.

The area that seems empty on a plan is often where the bins, the bikes or the drying happen.

Note every tree, large shrub and mature hedge near the marked area, including any standing on a neighbouring plot, and photograph each with the house in shot.

Vegetation near a proposed footprint is one of the first things a professional asks about, and photographs answer the question faster than words.

Whether a tree is protected, and what it means for work nearby, is for the local authority and a qualified professional to address, not for you to judge.

Record any stump within reach of the footprint, or the position of a tree you know was taken down, along with roughly when it happened if anyone remembers.

A tree that is no longer there still forms part of the site history, and it is easy for nobody to mention it.

Note the driveways, paths and patios that would have to be lifted for the work, and whether any of them is the only route to the back of the property.

Losing the route to the garden matters to how everything else on site is organised, and it belongs in an early discussion.

Write down anything near the footprint that you want kept, whether a particular plant, a wall you like or a gate, and say so before work is planned around it.

Things nobody was told to keep are removed for good reasons by people doing their job properly.

Note any boundary wall or fence the new structure would come close to, who maintains it as far as you know, and what condition it is visibly in.

The condition of an old boundary wall becomes everybody's problem the moment work happens beside it.

Record whether a neighbouring garage, extension or outbuilding sits hard against the boundary near the marked area, and photograph it from your own side.

A structure on the other side of the line changes the conversation, and raising it yourself early is far less uncomfortable than hearing it later.

Work near a shared or boundary structure raises matters to confirm locally and with appropriate advice; nothing here indicates what applies to you.

Note how the existing internal floor sits in relation to the ground outside on that elevation, describing it as a step up, roughly level or a step down.

This plain observation frames the level discussion, and it can be made from the back door in a moment.

Decide and record whether you want the new floor flush with the existing one or whether you would accept a step between old and new space.

Households that have not decided this end up with whichever answer the construction produced, and only notice once the floor is down.

Ask what achieving a flush floor would involve given how the existing building is put together, and treat the answer as information rather than as a refusal.

The request is reasonable; what it takes to deliver it varies enormously between properties and is not something to assume.

What is possible at the junction between old and new is a matter for a qualified designer and engineer to establish on site.

Note the position of any airbrick or low level vent on the wall the addition would meet, and ask what would happen to each one.

Low level vents are easy to build over without anyone noticing, and they may be doing something that matters.

What a vent serves and what would be needed if it were affected is a question for a qualified professional, never an owner assumption.

Record how the existing threshold or door sill sits in rough owner terms at each door on that elevation, and photograph each one from outside.

Thresholds are the point where levels, drainage and weather all meet, and photographs of them are consistently useful.

Write down which existing doorway or window opening you imagine becoming the link between old and new space, and mark it clearly as a preference.

Where the two parts join affects the whole conversation, including what happens below that part of the wall.

Ask what would change about the scheme if the ground or the existing construction turned out to be different from what everyone expected, and who would decide.

Asking how a change would be handled, before it is needed, tells you a great deal about how a project is being run.

Ask whether any digging or investigation is likely to be proposed, who would arrange access, and what the ground would be left like afterwards.

Reinstatement after investigation is routinely unmentioned and then becomes a small disappointment in the garden.

Any investigation below ground belongs with a suitably qualified professional; do not dig alongside a wall to satisfy your own curiosity.

Note how anyone or anything would reach the marked area from the road, including gate widths in rough terms, steps, slopes and overhead wires or branches.

Access shapes what approaches are practical here, and it is entirely observable by an owner before anybody visits.

Record which decisions you are being asked to make before anything below ground has been established, and flag them plainly in the conversation.

Some of those decisions are genuinely fine to make early; naming them lets somebody tell you which ones are not.

Ask that any assumption about the ground or the existing structure be written on the drawing or the note rather than carried in somebody's head.

An assumption in writing gets revisited when new information arrives; an unwritten one quietly becomes a fact.

Ask what options normally come up when the straightforward approach is not available in a situation like this, purely so the vocabulary is familiar later.

Hearing the range of possibilities early makes a later conversation much less alarming, without committing anyone to anything.

Keep a dated note of every conversation about foundations, who was present, what was said and what was left open at the end of it.

Notes written straight after a conversation are the only version anyone can rely on once accounts start to differ.

Ask for anything that changes the scheme to be confirmed in writing, and note when a point exists only as something somebody said on site.

Site conversations are where projects actually change direction, and they are the least well recorded part of any project.

Keep every version of a drawing with its date rather than replacing the old one, so it stays possible to see what changed and when.

Foundations get revised more than most parts of a scheme, and an undated pile of drawings makes that impossible to follow.

Where two people tell you different things about the foundations, write both down and take the difference back to them rather than choosing between them.

Choosing between professional opinions is not an owner role, and it is how a project acquires a problem nobody owns.

Resolving conflicting professional advice belongs with the professionals involved; ask them to reconcile it rather than picking the answer you prefer.

Record what each person has asked you to provide, whether you have provided it, and what is being held up while it is outstanding.

Projects stall on small items owed by the owner far more often than anyone admits afterwards.

Keep a short running list of the foundation questions that are still open, and read through it before any decision that would be difficult to change.

A visible list of open items is the simplest protection against a decision being made around a gap in the information.