By Guy Taylor Profit at Howdens rose by just £400,000 as it grappled with “challenging” conditions in the UK’s kitchen and joinery markets. Pre-tax profit came in at £112.3m, in line with management expectations and following some £16m in investment during the period. Operating profit rose just £200,000 to £117.2m. Revenue rose 4.3 per cent to £966.3m. Chief executive Andrew Livingston said: “Howdens performance in the first half was encouraging and we gained market share in a challenging marketplace. We continued to invest in our strategic initiatives which is strengthening our differentiated…