Risk of heave - oak tree removal

[Jj_1274]

Hi all 

 

I’m in the final stages of purchasing a house in south-east London with a large oak tree (approx. 16m in height) planted 1.2 metres from the side of the house. I have consulted with both a tree consultant and an engineer and have received the following advice.  

 

• The tree consultant has advised that the tree is c.65 years old, and was approx. 20 years old when the house was built in the mid 1970s (so it could be assumed that some sort of tree root protection was built in). 
• The engineer has reviewed a drawing from when the house was built, and the house is on 0.9m deep concrete strip footings. There is a further approx. 0.5m of brickwork before ground level (where the base of the tree is). The portion of the house nearest the tree is single storey.  
• The engineer has said that there are no signs of visible cracking on the brickwork or obvious damage to the structure from the tree to date, although there may be pressure against the foundations which cannot be assessed without an intrusive survey. 
• The house appears to be on Harwich Formation ground, but close to London Clay (anecdotally, it appears to be c. 1.5m sandy gravel over a bed of silty clay – the silty clay has medium to high shrink/swell potential). 

 

The tree consultant has advised that the tree has a remaining lifespan of c. 15 years before needing to be felled, due to proximity to the house and it’s condition. 

 

Given the above, is heave likely if the tree is felled (I would probably cut it down sooner rather than later)? Would appreciate a few opinions on this. Would people be walking away from this purchase? 

 

Thanks.