Extensions in Shrub End

Extending in Shrub End

The deepest back gardens on this side of Colchester, sitting on ground that has been dug for gravel and defended since the Iron Age.

Shrub End spreads south west of the town between Layer Road, Straight Road and Shrub End Road, about two and a bit miles out. It reads on the street as ordinary Colchester suburbia, and underneath it is anything but ordinary. Two of the things that decide a job here are invisible from the pavement: what was taken out of the ground in the last century, and what was put into it two thousand years ago.

Colchester City Council is the planning authority and Colchester City Council Building Control is the body we notify. This is unparished Colchester, so no parish council sits in the consultation chain, though the western fringe runs up against Stanway parish and applications close to that line pick up a consultee that streets further in do not.

The housing, in two waves

Speculative semis between the wars, then the largest of Colchester’s post-war council estates.

The first wave was private and piecemeal. Through the 1920s and 1930s small builders bought frontages along and between Maldon Road and Layer Road and put up pairs of semis a few at a time. Gladwin Road is the standard example: several firms working the same street, so the houses rhyme rather than match. Bay fronts, hipped tiled roofs, shallow strip footings, and long narrow plots because the land was sold by frontage.

The second wave was the council’s, and it was much bigger. After the war Colchester housed around 3,600 people in roughly 1,250 new houses on 95 acres at Shrub End. That is a single planned estate, laid out with wide verges and open frontages, built to a handful of repeated types, and sold largely into private hands from 1980 onwards. Cut roofs with purlins, cavity brick walls, square gardens, and side access on most of the pairs. The council’s other big post-war estate went up at Monkwick, in Berechurch.

There is a third, smaller layer: the housing built on the site of Colchester United’s old Layer Road ground after the club left in 2008, and other infill of similar date. Newer houses often carry conditions on the original permission that strip out permitted development rights so the estate stays as approved, and that condition binds the house rather than the first owner. It is worth reading the decision notice before assuming a rear extension is automatic. Our guide to planning conditions explains what they can and cannot do.

Long, thin, and what that is worth

Garden depth is the reason this is good extension country, and garden width is the reason it still needs designing.

The interwar plots in particular run a long way back for their width. That combination is unusually favourable for one specific test: permitted development limits how much of the land around the original house you can cover, and half of it is the ceiling. A deep plot gives you room under that ceiling that a square plot does not.

Depth is capped separately. A single storey rear extension under the standard permitted development limits reaches three metres on a semi or terrace and four on a detached house, and the prior approval procedure for a larger home extension doubles both, subject to a neighbour consultation period. On a Shrub End garden those larger figures are usable in a way they are not on a tighter plot, which is why six metre rear extensions are more common here than in most of the city.

Width is the constraint people miss. A narrow plot means the extension sits close to both boundaries, and that is where the daylight and outlook tests bite: officers assess the effect on neighbours with lines drawn at set angles from their windows, commonly at 45 degrees on plan and 25 degrees in section, and a long extension on a narrow plot can fail those before it comes anywhere near a size limit. The 45 and 25 degree rules are worth understanding before the design is fixed rather than after it is refused. The practical answer is often to step the extension in on the neighbour’s side, or to drop the roof to a lower pitch as it approaches the boundary.

Ground that has been dug

Shrub End had gravel pits and it has a landfill. Both leave ground that a strip footing cannot be assumed onto.

The natural sequence here is granular material over London Clay, and the reason it was worth extracting is that there is a lot of it. The Shrub End gravel pits were worked for decades, and some of what came out of them was replaced with whatever was going, in an era when nobody recorded it. There is also a landfill site on the south western edge.

Made ground behaves differently from undisturbed ground in two ways that matter. It settles under load, unevenly and for a long time, so a foundation bearing on it will move even when the design is right for the depth. And where the fill contains anything degradable, it can generate gas, which is why sites near historic landfill attract conditions about gas protection measures and verification.

None of that stops anyone building. It means the foundation gets designed from a hole rather than from a drawing: dig a trial pit, find the undisturbed material, and either found through the fill to reach it or use a design that spans it, which on a bad plot can mean a piled foundation with a suspended slab. That decision is worth more than any other line in a Shrub End quote, and a price built on a nominal one metre dig is not a price for the job. The foundations guide sets out what each type is solving.

On the plots that are genuinely on clay, the usual Essex rules apply: 900mm to 1.2m clear of trees, deeper near a mature one, with the depth set by the species, its mature height and its distance from the wall.

The dykes under the back gardens

A scheduled Iron Age monument runs through residential gardens here, and it is not a theoretical problem.

Shrub End sits inside the earthwork system that defined Camulodunum, the Iron Age territorial centre that Roman Colchester was founded next to. Heath Farm Dyke, Kidman’s Dyke, the Triple Dyke and the Shrub End Dyke are all part of it, and several lengths are scheduled monuments.

One of them makes the point better than any general warning. Heath Farm Dyke Middle is scheduled where it runs north east to south west through the garden of a house immediately south east of 43 Alan Way, as a ditch with a low bank on one side, together about ten metres across and about a metre and a half from ditch bottom to bank top. When a two storey side extension and single storey rear extension were built at 43 Alan Way, the work was carried out under archaeological monitoring.

Two separate controls are in play. A scheduled monument cannot be disturbed without scheduled monument consent, which is a national process handled separately from planning and is a reason to design around the feature rather than through it. Away from the scheduled lengths, the buried archaeology is dealt with through a condition on the planning permission, and in practice that usually means an archaeologist watching the foundation trench being dug and recording what appears. It is a known cost and a known number of days. It is only a problem when nobody allowed for it.

Gosbecks Archaeological Park, the Iron Age and Roman site with the largest known Roman theatre in Britain, lies immediately south west of the housing, off Maldon Road. That is the scale of what this ground was.

Roofs and lofts

Both waves of housing here have roofs that were cut on site, which is the version worth converting.

Interwar and early post-war roofs are built from rafters, purlins and a ridge, leaving a clear void that an engineer can open up without replacing the whole roof. That is the difference between a loft conversion and a re-roof, and it is why the loft is a serious option on most of this stock.

The hipped roofs on the interwar semis are the ones that need squaring off, because a hip cuts away the volume at the end where the headroom would be. Where there is enough height to start with, a rear dormer alone will do it, and on a long narrow plot a dormer is often the better answer than a deeper extension because it adds a bedroom without touching the garden at all. Our page on dormer loft conversions covers what the roof has to give you.

Access and the long barrow run

Getting in is easy here. Getting to the far end of the garden is the part people underestimate.

Most houses in Shrub End have a side gate and a driveway, so a skip stands on your own ground rather than on the highway with a permit, and materials come round the side. That is a genuine saving against the terraces closer to town.

What the long plot adds back is distance. Spoil from a deep foundation has to be moved, and on these gardens there is nowhere to put it except out at the front, which means barrowing or a conveyor and a grab lorry. On a plot with made ground the spoil volume goes up, because more of it is coming out. It is a small item on a small job and a real one on a deep foundation.

What people build in Shrub End

Rear extensions, usually deeper than average, and dormers where the garden is worth keeping.

The single storey rear extension is the dominant brief, opening the back of the house into a kitchen and living space, and the depth people can achieve here is what makes it worth doing. Two storey rear and side extensions turn up on the wider post-war plots.

Loft conversions come a strong second, particularly on the interwar semis where a hip to gable and a rear dormer produce a proper double bedroom. Garage conversions run behind both, and as on any estate of this date the first question is whether the garage is attached to the house or sitting in a block down the road.

Questions we get asked in Shrub End

How far back can I actually go?

Three metres on a semi or terrace and four on a detached house under the standard permitted development limits, doubled through the prior approval route with a neighbour consultation period, and subject to the rule that additions must not cover more than half the land around the original house. On these gardens the size limit is rarely what stops you. The neighbours’ daylight usually decides it first.

Is my garden on the old gravel workings?

It is a records question first and a trial hole question second, and both get done before a price is issued. Fill is not a reason not to build. It is a reason to design the foundation properly.

Will an archaeologist have to attend?

In parts of Shrub End, yes, through a condition on the permission. It normally means a watching brief while the trench is dug. Where a scheduled length of dyke is involved the position is stricter and the design works around it.

Can I convert the loft without planning permission?

Often, within the permitted development volume allowances and provided the dormer is at the rear rather than facing the road. It is worth confirming with a lawful development certificate rather than assuming, because a loft also brings Part B into play and turns the stairwell into a protected escape route.

Getting a price for a Shrub End extension

We are based at West Bergholt, a short run round the north and west of the town.

Our team surveys the property properly: the ground and what the records say has been done to it, the roof structure, the existing footings where they can be seen, the drain runs, the boundary relationships that will drive the daylight assessment, and the access. Most people who call us already have drawings and permission and want a builder to price the work and build it. That is the ordinary job here, and we are glad to work to somebody else’s plans. Where the drawings do not exist yet, we bring in the technician who draws it and the structural engineer who calculates it, we manage the planning route with Colchester City Council, we notify Building Control, and we run the job as main contractor.

We carry £2m public liability cover and build to current Building Regulations, through to the completion certificate. The survey and the quotation cost nothing.