■ A notable transaction to complete in March saw Sidley Austin pre-let levels 12 - 20 (133,776 sq ft) at TH Real Estate's new development 70 St Mary Axe, EC3. The international law firm will be moving their entire operations from their current residence at Woolgate Exchange, EC2 after the scheme achieves completion in Q1 2019.

■ Also in March, Charles Taylor Plc signed on 70,591 sq ft across the upper ground, ground and first floors on a 20-year lease at a rent of £57.50/sq ft. The insurance company will be consolidating from various offices including Lloyds Chambers, 1 Portsoken Street, E1. There is still 172,400 sq ft of available space in 3 Minster Court, EC3 across levels 2–8.

■ So far this year, we have seen good levels of demand from the Insurance and Financial services and the Professional services sectors, who have accounted for 32% and 20% respectively. However, the Serviced Office Provider sector has been quiet, accounting for just 4%.

■ The Tech & Media sector have continued to take space, accounting for 14% of Q1 take-up. Interestingly, 70% of the 197,000 sq ft let by this sector was taken in the City core, as opposed to their traditionally favoured northern and eastern fringe market.

■ Total City supply stands at 7.5m sq ft at the end of Q1, equating to a vacancy rate of 5.9%, which is up on this point last year by 40bps, but down on the 10-year average by 70 bps.

■ Following 200,000 sq ft going under-offer in March alone, there is currently 1.4m sq ft under-offer in the City.

■ The average prime rent for Q1 is £79.79/sq ft, which is up on the prime rent for Q4 2017 by 2.3%. This has been partly aided by the top rent of £94.00/sq ft being achieved when Jellyfish acquired part level 28 (9,752 sq ft) at The Shard, SE1.

■ The differential between the average Grade A rent of the City core and the City fringe has increased to £3.65/sq ft. This is due to the City core rising to £62.50/sq ft for Q1, while the fringe fell to £58.85/sq ft.

■ The average months rent free on a 10-year lease in the City remains at 23.

■ As a result of good pre-letting activity, the development pipeline is now 30% pre-let from now until the end of 2021. This will assist in keeping the vacancy rate low, and countering a potential dip in take-up over the next two years as the market moves through the cycle.

Analysis close up

^{Demand figures include central London requirements}

_{Completions due in the next six months are included in the supply figures}

_{* Average prime rents for preceding three months}

_{** Average rent free on leases of 10 years for preceding three months}