Step-Free House to Garden Threshold Questions Checklist

Write down who needs the level access and what they need to be able to do, including whether anything is wheeled through the opening.

A requirement expressed as a use can be met in more than one way, whereas a requirement expressed as a detail closes options early.

Note whether the need is current or anticipated, and whether the design has to work immediately or be capable of being adapted.

Those are different briefs, and saying which one applies changes what is worth committing to now.

Record which opening this is about, and whether another opening could serve the purpose more easily than the one you had in mind.

Owners fix on one door early, and a different opening is sometimes far less constrained by everything below it.

Note what happens beyond the threshold, since level access at the door is of little use if the route onwards has a step or a slope.

The threshold is one point on a route, and the route is what the requirement actually concerns.

Note that the requirement runs in both directions, including getting back in when it is raining and the surface outside is wet.

Thresholds are usually discussed as an exit and lived with as an entrance, which is where the water arrives.

Write down what you are willing to change inside as well as outside, including floor finishes, doors and the area immediately within.

The available room at a threshold is shared between inside and outside, and saying what is negotiable widens the options.

Photograph the doorway from inside and outside, and take a low photograph along the line where the surface meets the frame.

The junction is the subject, and a photograph taken along it shows more than one taken from standing height.

Record how the levels differ at present, using something permanent nearby as a reference rather than estimating the difference by eye.

A comparison against something fixed is repeatable and can be checked, whereas an estimate cannot.

Note what kind of door it is, how it opens, and whether the frame sits on anything visible below it.

How the door works is part of the threshold question, because the hardware needs its own clearance.

Record what the outside surface is, how far it extends, and whether it appears to fall away from or towards the building.

Which way the surface falls is one of the more useful observations and one an owner can confirm during rain.

Watch during heavy rain and note where water runs at the doorway, whether it stands anywhere, and whether it reaches the frame.

The existing behaviour is the baseline for everything proposed, and it is only observable in the right weather.

Note any channel, gully, grating or gap in front of the opening, and whether it appears to be doing anything during rain.

Something already present may be doing more than it looks, and it belongs in the record before anything is changed.

Ask where the damp course line sits at this opening and what that means for how high the outside surface may be.

This is the constraint that most often defeats the obvious solution, and it is a question rather than something to work out yourself.

Where a damp course line sits, and what the external level may do in relation to it, is a professional determination confirmed locally.

Photograph any vent, airbrick or low-level opening near the doorway and note how far above the surface each sits.

These have to keep working, and they are easily buried by a surface raised for entirely good reasons.

Ask what the wall construction is at this point, since what the outside level may do depends on it rather than on the surface.

The answer belongs with somebody qualified, but the question is the right one for an owner to arrive with.

Note whether the ground outside has already been raised at some point, and whether anything suggests it sits higher than it once did.

Previous raising narrows what is available now, and evidence of it is sometimes visible to an owner who is looking.

Ask whether lowering the outside surface, rather than raising it, is available here at all, and what doing so would involve.

It is the other half of the same question and it is frequently not raised, particularly by whoever is quoting for paving.

Lowering ground against a building or near any structure holding a level is a question for a qualified professional first.

Note what the floor construction is immediately inside, and whether anything inside the opening constrains the level as well.

The room available is shared between both sides of the opening, and the inside half is often forgotten entirely.

Establish whether there is occupied space beneath the outside surface, and record what you are told rather than assuming from the layout.

This single fact changes the whole conversation, and it is the first thing to settle before anything else is discussed.

Where there is, note that the surface outside is a roof and that lowering it is simply not available as an option.

Owners reasonably think of it as a terrace, and writing down that it is a roof reframes every subsequent question correctly.

Ask what is competing for the height available at the threshold, and record the answer rather than proposing a way to find more.

Several things need the same vertical room, and understanding that they compete is what stops an owner pressing for the wrong answer.

Note that a level threshold is not achieved by reducing the waterproofing turn-up, and record that as something you have been told rather than negotiated.

It is the shortcut that looks like a finish decision and moves the problem onto the part nobody can see.

How water exclusion is achieved at a level threshold over occupied space is professional design work and must not be adjusted on site.

Ask what the existing build-up outside consists of and whether any record of it exists, since a later owner sees only paving.

A terrace over occupied space is one of the constructions most worth having a record of and least likely to have one.

Where the space below belongs to somebody else, note that and ask what agreement or notice is involved before anything is changed.

Work on a surface above somebody else's rooms is not solely your decision, and it is better established at the start.

Work on a surface above space belonging to somebody else may carry legal obligations; confirm these with a suitably qualified adviser.

Ask what is proposed to intercept water travelling across the surface towards the opening, and whether it is part of the design.

Interception at a level threshold is a design element rather than an adjustment made on site, and asking establishes which this is.

Ask separately what deals with rain driven against and past the door itself, since that is a different question from surface flow.

The two arrive by different routes, and an answer covering only one of them leaves the other unaddressed.

Ask where anything intercepted at the door actually goes, and what happens when whatever receives it is already full.

Interception is only worth having if it discharges somewhere that will not back up during the storm that matters.

Where the surface sits over occupied space, ask how the arrangement at the surface relates to the outlets at the level beneath.

Draining the visible surface and draining the roof are not the same thing, and the distinction is easy for an owner to miss.

Note what shelter exists over the opening, such as a canopy, an overhang or a recess, and ask how much the detail relies on it.

Exposure matters as much as height at a threshold, and an owner can describe the shelter accurately without any technical judgement.

Ask whether anything proposed at the threshold affects the insulation around the floor edge, and what that means inside.

A decision made for drainage at the threshold can be a decision about the internal surface as well, which is worth knowing.

Ask whether any grating or cover at the threshold can be lifted and the channel cleared by the household without specialist help.

Something that cannot be reached silts up and becomes a shallow reservoir held against the door.

Ask how often clearing is expected to be needed, and whether that changes with the season or with what grows nearby.

A regime nobody mentions is a regime nobody performs, and the frequency is part of what you are taking on.

Write down who in the household would actually do the clearing, and whether the position is reachable by that person.

A threshold designed for level access should not require somebody to kneel in an awkward position to keep it working.

Note what regularly lands near the opening, including leaves, soil washed down from a bed, gravel, or debris from nearby planting.

What arrives determines how quickly anything at the threshold fills, and it is entirely predictable from the existing garden.

Ask what the surface immediately outside is like when wet, since it is crossed at the point where everybody is moving between levels.

The threshold is the busiest and most weather-exposed part of the surface, which is worth raising while materials are still being chosen.

Ask what you should watch for at the threshold once it is finished, and what would be worth reporting rather than living with.

Owners tend to accept a threshold that has started to hold water, and knowing in advance what is worth raising prevents that.

Ask whether a single agreed reference level exists for this junction, and whether it has been recorded and shared with everybody.

The door is made to its own tolerances and the surface is laid to site tolerances, and the datum is what reconciles them.

Ask what has to be decided before the door and the surfacing are ordered, and what could not be changed afterwards.

Ordering before the datum is agreed is the sequence that most commonly produces a threshold nobody is happy with.

Ask who is responsible for the threshold junction as a whole rather than for the door, the surface or the waterproofing separately.

A junction between three trades with no owner is where responsibility disappears, and an owner can ask the question early.

Ask for the agreed levels and the junction detail to be recorded in a form you can keep with the property.

A later owner sees paving and a door, and the record is the only thing that explains what is between them.

Note that any later change to the surface outside could affect the threshold, and write that down for whoever owns the property next.

Resurfacing outside is treated as a finish decision, and at this junction it is not one.