课题的第二部分是基础研究。这是一个非常耗时的工作，需要大量的测试数据支撑。在门窗方面，我们需在不同的窗墙比下进行不同的研发，包括上下游产业、原材料的供给，涉及到几百家企业，而且每一类产品的覆盖面不一样。尤其是针对北京地区，包括玻璃配置的要求，什么玻璃更适合北京？什么型材更适合北京？需不需要外遮阳等，我们对这一系列问题进行了系统的总结。
The second part of the project is fundamental research. This is an extremely time-consuming job that requires support from large quantity of test data. With regard to doors and windows, we need to do R&D work including upstream and downstream industries and supply of raw materials with different window-to-wall ratios. Hundreds of enterprises are involved, and the coverage of each category of products also varies. Particularly for the Beijing area, what kind of glass suits Beijing best in view of the glass configuration requirements? What kind of profiles is more suitable for Beijing? Are external shading facilities necessary? So on and so forth. We have made systematic summaries about this series of problems.

第三部分是系统介绍。我们的图集收纳了铝、塑、铝木复合这三类窗，每类中挑选出6种窗，分别从K值=1.5到2.0逐一进行介绍。
The third part is the systematic introduction. Our portfolios collect and introduce three categories of windows (aluminum, plastic and aluminum-wood composite). 6 types of windows are selected for each category with the K value varies from 1.5 to 2.0.

75%建筑节能政策下的门窗发展趋势
Development trend of doors and windows against the 75% building energy conservation policy

北京市在75%建筑节能标准方面对门窗的要求是K值在1.5到2.0 这个范围之间，具体数值根据建筑的不同使用要求而有不同变化。现在实现这一标准还是有一些困难的，在这里要分为两个部分，一个是技术方面，另一个是管理方面。
According to the 75% building energy conservation standard, the requirement of Beijing for doors and windows is that K =1.5 to 2.0, depending on different utilization requirements of buildings. There are still some difficulties in realizing this standard at present. The difficulties are divided into two aspects here: technical and management.

首先，在技术方面，例如对铝窗来说，随着K值的降低，它的成本将大幅上升，塑窗K值达到1.5就相对容易很多，而铝木复合窗是介于这两者之间的。我们肯定要根据不同的窗型考虑如何达到最优性价比，降低K值。
Firstly, from the technical aspect, with decrease of the K value, the cost of aluminum windows will go up dramatically while it is easier for plastic windows to have the K value reduced to 1.5, and the difficulty degree for aluminum-wood composite windows falls in between. We certainly have to consider how to reach the optimal cost performance and lower the K value based on different kinds of windows.

其次，也是最重要的是在管理方面的困难。我们在课题中也对管理层提出了建议，随着标准的提升，工程造价的定额也一定要跟着提升，不然就会陷入恶性循环，技术方面的指标就是白定。厂家只会拿着不达标的产品滥竽充数，因为他们是不可能做亏本生意的，600元的定额想买到成本800元的东西，那是不可能的。
Secondly, the most important difficulty lies in management. We have proposed suggestions to the management. For instance, the quota of project costs should increase with the promotion of standards; otherwise, the enterprises will be trapped in a vicious cycle and the technical indicators will be set for nothing. In that case, the manufacturers will only make up a number with substandard products, because they will never make bad bargains and it is impossible to buy materials worth 800 yuan with the quota of 600 yuan.