Ask the experts

1.How can we meet building control’s airtightness requirements?

We finished a self-build last year and we’re only now getting round to applying for a completion certificate. Building control requires a Q50 airtightness result between 5 and 7. Our test has come in at a much better 2.79 – which we’re told is too good! I’ve been informed that it’s not as simple as just inserting a couple of vents and that we may have to strip plasterboard from the walls and remove the seals from the joins between the walls and floor. In the house plans, the SAP calculations state a figure of 7 for the Q50. Unfortunately, due to disputes, we parted ways with the architect before the end of the project. Do you know of a less drastic way of getting the Q50 figure up to 5?

I’ll confess that this sort of situation is new to me and I’ve had to ask my professional contacts for their take on it. It seems a real shame to have to take retrograde action when a house has been built to such impressive standards, but it points out the perils of working to high levels of airtightness without professional guidance. I’m wondering if parting with your designer at a crucial stage has led to this situation, because no architect I know would have sanctioned building to this standard without specifying a mechanical ventilation and heat recovery (MVHR) system to maintain the levels of fresh air required inside the home. As you have no doubt discovered, retrospectively installing MVHR is expensive and disruptive, which is why it needs to be considered during the early design stages. My building control friend Paul Kalbskopf has suggested discussing the possibility of installing stand-alone units with building control.

2.Can I move my neighbour’s electricity supply?

I recently bought a steading (with planning permission to convert it to a house) and I need to re-route my neighbour’s electricity supply, which currently runs over the top of the building. Previously, both our properties were under joint ownership, before being sold off. I contacted SSE and they quoted £7,500 to bury the cable. Do I have any legal ammunition in my favour that I can use to persuade my neighbour to bear some of the cost?

I am afraid that this enquiry is most suited to a lawyer, as you are questioning the right of your neighbour to have electric cables running above your property. My own view is that, if this was being proposed now, you would have every right to prevent your neighbour from negotiating an overhead supply across your land to service their dwelling. However, you have recently acquired the steading with the overhead line already in position. One would assume that consent must have been agreed as a result of both properties being in common ownership. I would suggest that you have no right of recovery for the cost of moving these services underground but you may be able to appeal to the good nature of your neighbour for a contribution. My own experience with utility companies is that their fees are generally negotiable and if you feel their quoted sum is too high, I would tackle the matter directly with them as it may lead to a reduction.

3.What’s the best way to appeal a planning refusal?

We’ve recently had our planning application denied. We disagree with the reasons the council gave and are hoping to appeal the decision. Has anyone had any experience with appeal companies? Is it best to go with a business that uses town planners or a law firm that specialises in this area?

It is advisable to seek professional advice with an appeal, as it is very much the option of last resort. Who is best to go to depends on the nature of the case, but generally planning lawyers come into their own where the issues are complex and not ease like putting a baby in a double stroller for infant and toddler and there are legal matters to consider. For most appeals concerning new dwellings, or alterations to existing ones, consultants (who may be chartered town planners or planning and development surveyors) are the best choice and would generally be a less expensive option.

4.How do I ensure the eaves of our home are sufficiently airtight?

We’re self-building a timber frame house. The roof and tiles are now on and we’re bricking up the exterior. My brickie advised me to put an expanding foam strip between the top course of bricks and the soffit (at a cost of around £500), as this allows for the timber frame to settle. Could I get away with just pointing the junction instead?

Your bricklayer is giving you good advice for a typical softwood (open or closed panel) timber frame. I spoke to Simon Orrells at Frame Technologies ( and he confirmed that you can expect 5-6mm of settlement per storey on a timber frame structure over the first few years, so a 10-20mm thick expanding foam strip would be required. A specialist tape such as Compriband should be used. I’m afraid it is not cheap at around £5 per metre but it is self-adhesive and very easy to lay, so there shouldn’t be a huge labour cost attached. I don’t know the size of your project, so I can’t say if £500 is a fair price or not, but it doesn’t sound too far off the mark. Work out a sensible price based on the perimeter of your walls and allow for a couple of hours of labour to apply the tape. I also spoke to Oakwrights ( and they confirmed that if you are using an oak frame with infill panels, they would employ expanding foam seals. Tese are installed as the structure is erected and are included as part of their package

Ambitious Endeavour

Jessica and Ron Spelton are keen to self-build, but would also like to make some money from the exercise. One way to achieve this, perhaps, would be to buy a larger plot, subdivide it into two or three and then sell on the other segments, possibly having put in services to add value. It’s a […]

Plumbing and Period Homes

Mains utilities supplies are relatively new in the grand scheme of things, and the majority of older houses were built without bathrooms, running water or plumbed-in waste. What’s more, warmth was provided via open fires rather than modern boilers and other tech. So any refurbishment is likely to involve making significant upgrades to the plumbing […]

Insulating a new masonry home

Although there is a great deal of current debate about Building Regulations not changing fast enough to keep up with modern efficiency demands, the rules regarding external wall insulation are an exception. Gone are the days of simply picking an outer brick and an inner block and adding in some arbitrary cavity insulation; today, the process is a fine (and very calculated) art.

Cavity wall principles

Having two layers of brickwork with a space between them is known as cavity wall construction. This method was first introduced in the early 20th century as a way to provide better protection against penetrative damp and to help keep the inside of walls dry, so you can keep your funiture like your wooden shelf or best rated mattress dried without worrying them getting wet.

Dense concrete blocks started to be used for inner cavity layers after the Second World War, with lighter weight blocks (with air insulation) introduced in the 1960s and 1970s. A decade later and insulation started to be introduced into the cavities.

Wrong side of the river ( part 2)

There’s also the pollution. “Every bit of dirt that we have to take off the site and throw away is expensive, because it’s contaminated with metals and other things,” says the environmental scientist Justin Reel of RK&K, who leads mitigation and hydrological planning for the project. “But for the low-level type of human interaction we’re proposing, with a fairly thin cover we can use it on the site effectively. If you don’t have frequent, regular, intended exposure, these contaminants aren’t super bad. Where we do anticipate frequent soil contact, like our upland islands, we are planning for a cover over top of any native soil.”

[caption id="attachment_236" align="aligncenter" width="618"] South Wilmington Wetland Park Master Plan[/caption]

A single strategy

But resolving the polluted soil problem will be complex. “It’s one thing to clean up an area for humans. But if you’re bringing burrowing animals in, or shellfish,” a more stringent standard might be required, says Marian Young, the president of the remediation consultancy BrightFields. Scarfone quips, “For the amount of remediation we need, all the earthworms in the world aren’t going to be able to do.” Normally, he says, “for projects like this, you cap it. But here, we want to re-create a functioning system.”

This spring, the future park was cleared of dense Phragmites. The resulting open, savanna-like vista gave a delightful hint of how it might eventually look—or feel, anyway, because it has yet to be sculpted and engineered.

[caption id="attachment_237" align="aligncenter" width="657"] Industrial detritus and invasive vegetation have occupied the site until now.[/caption]

Added water storage capacity and created habitats that can resist recruitment of invasives like Phragmites will both be achieved with a single strategy, lowering the site to alter the hydrology and establish “a different water regime than we have right now, which is very irregular and storm driven,” Reel says.

When there is a flush of stormwater from the residential neighborhood, it will collect in a forebay, to let sediment settle, and then will cross the site through a winding network of channels and ponds. These eventually converge on a short, straight connection from the park to the river that is partly open ditch and partly pipe.

At the river, the flow, as it is currently, will be controlled by a self-regulating tidegate. An open flow to the Christina and its tides was considered. That would promote the wetland’s naturalization and its connection to fisheries. But properties surrounding and contiguous to the park are low-lying.

Wrong side of the river ( part 1)

The Christina River is a tributary of the mighty Delaware estuary, close enough to the ocean that it is tidal. It meanders through Wilmington like a wobbly M. Most of the city sits on the north shore. As long as anybody can remember, the lowerlying south side has experienced periodic inundation; 90 percent of it is within the 100-year floodplain. The first European settlers, being Dutch, were undaunted.

They built dikes and ditches there, and grew salt hay for fodder. Iron mills, coal yards, tanneries, and other nastiness arrived on the south shore throughout the 19th century and into the 20th, mostly located along the river’s edge. Mean-while, in the marshy center of the M, according to an 1893 newspaper item, there were eight or 10 “flower farms,” the largest named Rushland Gardens.

[caption id="attachment_229" align="aligncenter" width="1268"] RANDALL’S ISLAND The trestle beneath Hell Gate Bridge on New York’s Randall’s Island,[/caption]

A street grid was platted for this whole river-bound southern piece of Wilmington, but only a sliver of it, a neighborhood called Southbridge, was ever developed. In 1900, when the city’s total population was nearly 77,000, about 3,000 people lived south of the Christina.

Many were recent immigrants, and some were African Americans with deep local roots; the first independent black Christian church in the United States, the Union Church of Africans, had been founded there by a former slave in 1813.

Today, industry in South Wilmington appears to consist largely of auto junkyards and storage lots for disused trailers and shipping containers.

[caption id="attachment_230" align="aligncenter" width="465"] High tides and a clogged sewer overflow system frequently combine to flood Wilmington’s low-lying Southbridge neighborhood.[/caption]

Recently there’s been some growth—a shopping center with a supermarket, and a waterfront town house and apartment-tower complex built along the northwestern edge, facing over the Christina to downtown and the city’s thriving Riverfront redevelopment district.

Half a mile east, though, across the wetland, Southbridge feels like an isolated village. Its population has dwindled to about 1,500, nearly all of whom are African American. But it’s a place with a certain integrity. Many families have lived there for generations.

Nearly half the homes are owner occupied. There is an active and effective neighborhood association. Still, it floods. Now there is a plan to transform the marshy center into South Wilmington Wetlands Park. It’s not exactly a new proposal. A 2006 neighborhood plan offered a description that still applies: “Create a Central Park located to the immediate west of Southbridge.

Use this park as the lungs of the neighborhood. Its wetlands should be cleaned up and improved for flood retention.” But flooding is not the neighborhood’s only challenge. Southbridge is more or less surrounded by brownfields left over from those 19th and early 20th century heavy industries.

Near by jobs are few. It’s a food desert, with public health issues typical of underserved urban communities with an industrial past. The park vision has been enhanced since 2006, with a plan for added street connectivity around the wetland, and with realizations that a cross park trail will link the neighborhood directly to the shopping center and groceries.

The park could be an engine of investment, not only for Southbridge, but also for all the nearby underused properties. That could mean infill for new residents and businesses, and new jobs. Another added dimension: The concept of how to handle the wetland itself has been taken far beyond the basics of cleanup and water retention. The source of the flooding, aside from low elevation and inexorably rising tides, is an overwhelmed combined sewer system.

New Protocols Will Ensure The Genetic Diversity Of Threatened Trees

In what may be one of the largest tree conservation efforts in recent history, a team of environmental scientists from nine botanic gardens, arboretums, and environmental conservation agencies, as well as international collaborators in the Dominican Republic and Belize, is working to preserve and increase the genetic diversity of the country’s living tree collections. Launched in October 2016, the ambitious, three-year project is a form of insurance for endangered species.

Maintain the genetic diversity

[caption id="attachment_33" align="aligncenter" width="887"] Sinkhole cycad (Zamia decumbens) grows at the bottom of a sinkhole in Belize.[/caption]

“Zoos often have to exchange animals to maintain good genetic diversity across the population. Gardens are just starting to realize they have to manage plant collections in the same way,” says Patrick Griffith, the executive director of the Montgomery Botanical Center in Coral Gables, Florida, who is leading the effort. “We want to know what is the right number of plants to grow in botanic gardens if you want to maintain the genetic diversity of these plant populations.

With support from a $439,000 grant from the Institute of Museum and Library Services, researchers are collecting and analyzing DNA samples of endangered or threatened woody plants across a broad phylogenetic spectrum, including oaks, magnolias, palms, cycads, and Hawaiian alula (Brighamia insignis).

In Britain, Anglo-saxon Place-names Hold Hydrological Clues

One of the joys of travel, even of armchair travel, is the discovery of euphonious place-names. I’ve driven through both Humptulips, on Washington’s Olympic Peninsula, and Quonochontaug, in Rhode Island, and in both cases, these names, which I find flow off the tongue, flow in another way, too. Each describes the place’s hydrological characteristics.

Humptulips, in the tongue of the Chehalis Tribe, tells that it is “hard to pole” a canoe through the river, which follows a convoluted course that includes fast, narrow torrents. Quonochontaug (Narragansett for “at the long pond”) is along a string of broad, placid coastal lagoons.

[caption id="" align="aligncenter" width="800"]View towards the ruined St James Church at Bawsey (geograph 4255210).jpg Source: Wikipedia[/caption]

The guide that indigenous names can provide to landscape qualities and to human interactions with landscape may be followed any-where such names have not been erased by the conquest of colonialism. This is no less true in Britain, where four universities—Leicester, Southampton, Nottingham, and Wales—have joined forces under a grant from the Leverhulme Trust for a two-year study of place-names called “Flood and Flow.”

In Britain, an extra dimension to the record of place-names provides a set of clues to how particular land-scapes might respond to global warming in the near future. In the period between 700 and 1000 AD, temperatures in the British Isles rose rapidly after a cold phase that began in 400 AD.

Minneapolis Pilots A More Equitable Way To Fund Park Improvements

With its chain of lakes and acres of open space, Minneapolis has a nationally lauded park system. But as of 2015, its smaller neighborhood parks faced a capital investment backlog of more than $100 million, a shortfall that translated to aging structures, walkways full of potholes, and soccer fields that had been ground into mud.

[caption id="attachment_25" align="aligncenter" width="657"] A closed tennis court in Folwell Park.[/caption]

Vina Kay, the executive director of the Minnesota-based advocacy organization Voices for Racial Justice, says one can see an ugly pattern in which parks are in the worst shape. “If you were to go on a visual tour, you would see that some parks are more run-down than others and that those parks are most often in low-income communities of color,” Kay says. In response, the Minneapolis Park and Recreation Board recently developed what its members hope is a more equitable system of park priorities.